What is the author's attitude toward Hering's theory

A．scientists have reached a consensus on the relationship between brain processes and mental experience
B．variations in nerve cells are proved to be significantly correlated with mental experience
C．attempts to correlate mental experience with brain processes have been viewed with pessimism
D．scientists are indifferent to the manifold dimensions of mental experience

A．the developmental patterning of the neural circuits
B．the sensory field of the cerebral cortex
C．variations in size, shape, chemistry, conduction speed of nerve pulses
D．physiological correlates of mental experience