For Frequencies of Sound to Which Place Theory Applies, Neurons

For frequencies of sound to which place theory applies, neurons inform the brain of these frequencies by ______.

A) altering states of neural firing via fewer IPSPs occurring in inner hair cells
B) changing patterns of neural firing via lowered threshold of firing in inner hair cells
C) the region of the basilar membrane with maximal vibration and subsequently which neurons are firing most
D) changing the number of fibers activated and the pattern of volleying across different fibers