Answer:
Step-by-step explanation:
A: Softly, the members ...
Softly is an adverb. So A is your answer if there are no other adverbs beginning a sentence.
B: The instruments ... The is an article which is a kind of adjective. B is not the answer.
C: Tuning is a participle which is a kind of verb. Not the answer
D. Having is a participle. So this sentence is rejected for the same reason that C is.