What Does the Origin of Smiling Have to Do with Vocal

What does the origin of smiling have to do with vocal pitch?

A) Smiling lowers the pitch of your voice, causing you to sound calm and soothing, which is the auditory equivalent of a smile
B) Smiling prevents animals and humans from producing vocalizations, so it is a way to silently signal trust
C) Higher-pitch vocalizations can express friendliness and harmlessness, and altering your vocal tract to produce higher pitches results in a smile-like mouth shape
D) Smiling in humans and nonhumans is always accompanied by a vocalization