Question 27: Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction. (A)Read the letter(B) from her mother, she(C) feels very (D)happy.
Simplify adverb clauses: if the subject of both clauses is the same, we can shorten that clause
Active -> V-ing; passive -> V3/ed
Eg: When I see him, I will say that I love him.
=> Seeing him, I will say that I love him.
Answer A => Read -> reading (Reading the letter from her mother, she felt very happy.)
===============