In each of the following questions, sentences are given with blanks to be filled in with an appropriate word(s). Four alternatives are suggested for each question. Choose the correct alternative out of the four as your answer.
All of them are surprised __ her rudeness.

Options

A. with
B. upon
C. at
D. on

Answer

C

Explanation

Surprise (Verb) agrees with at (Preposition)
Here, at is the right usage.