I would go with answer choice D. "The chicken satay was very flavorful, but the curry was so fragrant and warming."
A compound sentence is basically a sentence made up of two smaller sentences or independent clauses. Meaning, if you broke this sentence into two, it would still make sense.
"The chicken satay was very flavorful."
"(But) the curry was so fragrant and warming."
I hope this helped a little bit.