单项选择题

She was so touched by his kind offer that for a moment she was ______ for words to express her thanks.
A) at a loss C) in question
B) out of control D) ill at ease

A.She was so touched by his kind offer that for a moment she was ______ for words to express her thanks.
B.at a loss
C.out of control
D.in question
E.ill at ease