Mark the letter A, B, C, or D on your answer sheet to indicate the und

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions. 
What I told her a few days ago is not the solution to most of her problems. 

• A. A. What I told her
• B. B. is
• C. C. to
• D. D. most of

Kiến thức ngữ pháp: ago → was  
Chủ ngữ là mệnh đề danh từ động từ chia số it : were – was