8036. As soon as he finished his speech, there was spontaneous applause from the audience.

✅ The correct answer is option C.
well-timed : occurring at an appropriate time; timely.

willing : ready, eager, or prepared to do something.

instinctive : (of a person) doing or being a specified thing apparently naturally or automatically.

instantaneous : occurring or done instantly.

spontaneous : performed or occurring as a result of a sudden impulse or inclination and without premeditation or external stimulus.

Synonym of spontaneous is instinctive