What Does the Neuronal Population Code Imply About the Motor

What does the neuronal population code imply about the motor cortex?

A) every neuron in the motor cortex is mapped exclusively to a specific population of other neurons
B) only specific populations of neurons in the motor cortex are responsive to electrical stimulus
C) movements are encoded on the motor cortex not by single neurons but populations of neurons firing together
D) only in certain populations of monkeys has motor cortex mapping been successful