Dear Teresa Silva, The official of the university has reported to us that you are an English major who meets the high standards for membership in Sigma Tau Delta. As is known, Sigma Tau Delta was founded in 1924 at Dakota Wesleyan University. It is an international collegiate honor societyfor students of English. It presently has over 850 chapters in theUnited States, Europe, the Middle East, and theCaribbean. Over 9,000 new members are admitted into the organization annually. Sigma Tau Delta's purpose is to promote literature and writing and to advance the study of the written word. Members gather annually in the spring at the international meeting to present papers and share experiences and ideas within the English subject. The Society offers tens of thousands of dollars in scholarships, awards, as well as publication chances in its journals The Rectangle and The Sigma Tau Delta Review. It is our pleasure if you can complete the application for Sigma Tau Delta membership. If you would like to be included in this spring's induction   ceremony, please complete the application form, and include amount to cover both local and international fees. Your completed form must be received by date to be considered for the upcoming induction ceremony.  We congratulate you on your outstanding academic record and hope you will join us as a Sigma Tau Delta member. If you want to get more information, please visit our website www.sigmataudelta.org, or give us a call. The phone number is 583-2864.  Sincerely,  Emily Lister This passage is basically a letter of   _  .
introduction congratulation thanks invitation
Question: Dear Teresa Silva, The official of the university has reported to us that you are an English major who meets the high standards for membership in Sigma Tau Delta. As is known, Sigma Tau Delta was founded in 1924 at Dakota Wesleyan University. It is an international collegiate honor societyfor students of English. It presently has over 850 chapters in theUnited States, Europe, the Middle East, and theCaribbean. Over 9,000 new members are admitted into the organization annually. Sigma Tau Delta's purpose is to promote literature and writing and to advance the study of the written word. Members gather annually in the spring at the international meeting to present papers and share experiences and ideas within the English subject. The Society offers tens of thousands of dollars in scholarships, awards, as well as publication chances in its journals The Rectangle and The Sigma Tau Delta Review. It is our pleasure if you can complete the application for Sigma Tau Delta membership. If you would like to be included in this spring's induction   ceremony, please complete the application form, and include amount to cover both local and international fees. Your completed form must be received by date to be considered for the upcoming induction ceremony.  We congratulate you on your outstanding academic record and hope you will join us as a Sigma Tau Delta member. If you want to get more information, please visit our website www.sigmataudelta.org, or give us a call. The phone number is 583-2864.  Sincerely,  Emily Lister This passage is basically a letter of   _  .
A. introduction
B. congratulation
C. thanks
D. invitation
Answer: