Which of the Following Is True

Which of the following is true?

A) A mutation in the DNA can be observed at the macroscopic level even if there's no change in phenotype.
B) Each biochemical pathway is governed by one gene.
C) A neutral mutation leads to no discernable phenotype.
D) A neutral mutation leads to a phenotype that can help or hurt the organism depending on the environment.
E) A neutral allele leads to a change in function in a protein that neither harms nor helps an organism.