Muscle cells differ from nerve cells mainly because they
a. express different genes.
b. contain different genes.
c. use different genetic codes.
d. have unique ribosomes.

a. express different genes.

Explanation:

The nerve cells is functional for controlling the coordination of the body, respond to the external stimuli, voluntary actions in the body. The muscle cells contract and relax to facilitate the locomotion.

All the somatic cells of a living being have the same genomic make up. However, completely differentiated cells of particular tissue lineages express distinct genes, as required so as to perform specialized functions in the body.

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.