Answer:
I think you should leave it as is. You italicize words to stress a meaning but to my knowledge, nothing needs stressing in that sentence. Hope it helps and sorry if it didn't. ♥
In expository writing, a topic sentence is a sentence that summarizes the main idea of a paragraph. It is usually the first sentence in a paragraph. What is your question regarding a topic statement?
Answer:
Begger asked why was i throwing stone at him.