Most children don't enjoy doing housework . Then like playing computer games rather than  cleaning the rooms. But in Australia, Jim and Robert's mother, Mrs Black, has a good and proper method to get their children to do housework. Here is an example.    "Mum, have you worked out next week's housework? Let Jim and me choose the cards. I can't wait. It's fun! "    When Robert shouted out, his mother had already put all the cards on their big table. On the  cards, there are some words like these, " sweep the floor, clean your bedroom, help mum cook,  wash vegetables, make beds, feed the fish, cut the wood, clean the bathroom " and many others. Jim and Robert chose two cards for each day from Monday to Friday. Then they would hang  them on the weekday task board. Jim likes to clean the bathroom, so he picked up the card "clean  the bathroom ". Robert loves to make the bed so he picked up his favorite card. Jim again picked  up "wash vegetables" and Robert chose " feed the fish ". Soon the two boys were happy to take  away all the cards.  To help the children do housework, their mother thought hard and came up with this idea. Of  course, the couple did the housework on the weekends and left Jim and Robert two days free. Who did the housework on the weekends?
Their mother. Their father. Their parents. The whole family
Question: Most children don't enjoy doing housework . Then like playing computer games rather than  cleaning the rooms. But in Australia, Jim and Robert's mother, Mrs Black, has a good and proper method to get their children to do housework. Here is an example.    "Mum, have you worked out next week's housework? Let Jim and me choose the cards. I can't wait. It's fun! "    When Robert shouted out, his mother had already put all the cards on their big table. On the  cards, there are some words like these, " sweep the floor, clean your bedroom, help mum cook,  wash vegetables, make beds, feed the fish, cut the wood, clean the bathroom " and many others. Jim and Robert chose two cards for each day from Monday to Friday. Then they would hang  them on the weekday task board. Jim likes to clean the bathroom, so he picked up the card "clean  the bathroom ". Robert loves to make the bed so he picked up his favorite card. Jim again picked  up "wash vegetables" and Robert chose " feed the fish ". Soon the two boys were happy to take  away all the cards.  To help the children do housework, their mother thought hard and came up with this idea. Of  course, the couple did the housework on the weekends and left Jim and Robert two days free. Who did the housework on the weekends?
A. Their mother.
B. Their father.
C. Their parents.
D. The whole family
Answer: