Best friends may be priceless but the cost of keeping the relationship alive is PS23,870. According to a study, a BFF (best friends forever) does not come cheap with devoted friends spending PS4,679 on birthday presents alone over a lifetime. And while it costs nothing to be a shoulder to cry on, _ Britons go the extra mile and spend PS168 on pick-me-ups  to get their mate through a rocky patch  like the breakup of a relationship. There's a further PS242 spent on presents to show how much they mean from gifts bought on holiday to treats for no reason. And distance does not break up a close friendship as BFFs spend a whopping  PS18,000 on travel to see each other despite being miles apart because of university, jobs and marriage. The study by cashback site TopCashBack found on average BEFs who marry can expect PS431 spent on them and a further PS283 on gifts when they have children. And they can rely on their pals to help out when they move houses as they will obtain PS127 worth of housewarming presents and takeaways(a kind of food). The survey based on a friendship lasting 40 years found more than eight in ten adults with a BFF felt their friendships were worth every penny. TopCashback spokesperson Natasha Smith said: "Those friendships which stand the test of time are often the most important in our lives. However, they come at a cost. From train tickets once a month to flights and a new dress for a wedding on the Italian coast, the price paid for having a best mate can soon add up. But when we asked people to compare their friendship with the financial investment , only 14% thought their friendship was equal to their investment with the vast majority thinking it was worth more." What is Natasha's understanding of BEF friendship?
It's costly and unaffordable. It's expensive but worthwhile. It's rewarding but hard to keep. It's changeable but worth possessing.
Question: Best friends may be priceless but the cost of keeping the relationship alive is PS23,870. According to a study, a BFF (best friends forever) does not come cheap with devoted friends spending PS4,679 on birthday presents alone over a lifetime. And while it costs nothing to be a shoulder to cry on, _ Britons go the extra mile and spend PS168 on pick-me-ups  to get their mate through a rocky patch  like the breakup of a relationship. There's a further PS242 spent on presents to show how much they mean from gifts bought on holiday to treats for no reason. And distance does not break up a close friendship as BFFs spend a whopping  PS18,000 on travel to see each other despite being miles apart because of university, jobs and marriage. The study by cashback site TopCashBack found on average BEFs who marry can expect PS431 spent on them and a further PS283 on gifts when they have children. And they can rely on their pals to help out when they move houses as they will obtain PS127 worth of housewarming presents and takeaways(a kind of food). The survey based on a friendship lasting 40 years found more than eight in ten adults with a BFF felt their friendships were worth every penny. TopCashback spokesperson Natasha Smith said: "Those friendships which stand the test of time are often the most important in our lives. However, they come at a cost. From train tickets once a month to flights and a new dress for a wedding on the Italian coast, the price paid for having a best mate can soon add up. But when we asked people to compare their friendship with the financial investment , only 14% thought their friendship was equal to their investment with the vast majority thinking it was worth more." What is Natasha's understanding of BEF friendship?
A. It's costly and unaffordable.
B. It's expensive but worthwhile.
C. It's rewarding but hard to keep.
D. It's changeable but worth possessing.
Answer: