Answer:
First you have to think of the most challenging thing youve ever done, here is a sentence starter: The most challenging thing i have ever done was...
Explanation: Example the most challenging thing i have ever done was when i ran in a had to overcome my fear of snakes.
Well, since Elaborate is a synonym for explain, I would guess that the student would just have to explain more about the topic.
The only correct answer is B) He spoke sharply to his sister.
A isn't correct because it should be - looked sadly.
C isn't correct because it should be - tasted bitter.
D isn't correct because it should be - feel well.