Read the sentence. i told them how surprised and excited i was to have my painting selected, especially since i’d felt so incompetent at the beginning and i knew the competition was so ruthless. which revision best uses dialogue to improve the sentence?

Unfortunately, you didn't share any options so that my answer could coincide with your option list given with the task, but  think we have got the same things. I am pretty sure that the  revision which best used in dialogue to improve the sentence is:

“Did you hear?” I asked them. “My painting got selected! Exciting, right?” I smiled.
Hope it will help you in some measure.

The answer is a criminal then