Question

You can use them to include explanatory words or phrases within quoted language:

a. commas
c. brackets
b. periods
d. all capitals

Answer 1

a. commas

A comma may be used correctly to do any of the following:
Examples:

When he came, his mother ran unto him.
Talking about bugs, I don't like any of them.
Hey, did you do the thing I told you to do?
if you don't know how to answer that, you can ask me for help.