Need !
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.

I'd choose this dialogue to revise your sentence:
“Did you hear?” I asked them. “My painting got selected! Exciting, right?” I smiled. “Especially given that I felt so incompetent at the beginning and that the competition was ruthless!”

It feels like the option that best uses the dialogue to improve this sentence, because the other options are either too informal or just the same sentence as the original one.

China plays a major role in population and china is also a well developed country