Indicate Which Type of Muscle Is Associated with the Property

Indicate which type of muscle is associated with the property in question by writing the appropriate letter in the blank using the answer code below:
-Is self-excitable.

A) skeletal muscle only
B) single-unit smooth muscle only
C) cardiac muscle only
D) skeletal muscle and cardiac muscle
E) skeletal muscle and single-unit smooth muscle
F) single-unit smooth muscle and cardiac muscle
G) skeletal, single-unit smooth, and cardiac muscles