Analogy type questions:
$(1)$ Red muscle fibers / White muscle fibers have fewer mitochondria but more sarcoplasmic reticulum.
$(2)$ When nerve impulses reach the neuromuscular junction,acetic acid / acetylcholine neurotransmitter is released.

• A
  $(1)$ White muscle fibers,$(2)$ Acetylcholine
• B
  $(1)$ Red muscle fibers,$(2)$ Acetic acid
• C
  $(1)$ White muscle fibers,$(2)$ Acetic acid
• D
  $(1)$ Red muscle fibers,$(2)$ Acetylcholine