How is the intensity of a stimulus encoded during information transmittal to the central nervous system?

A) Different second -order neurons transmit information about stimuli of varying intensities.
B) Different afferent neurons transmit information about stimuli of varying intensities.
C) The frequency of action potentials transmitted to the central nervous system is greater for a stronger stimulus.
D) The amplitude of action potentials transmitted to the central nervous system is greater for a stronger stimulus.
E) The neurotransmitter released from an afferent neuron differs based on the intensity of the stimulus.