Заполните пропуски, избирая вариант а или б. 1. I am surprised

I am surprised at his not answering at the last lesson. Я удивлен тем, что он не ответил на последнем уроке.

I was surprised at his not answering at the last lesson. (Past Indefinite).

I am not surprised at his not answering at the last lesson.

I was not surprised at his not answering at the last lesson.

Am I surprised at his not answering at the last lesson?

Who is surprised at his not answering at the last lesson?

I am surprised at his not answering at the last lesson, are not I?