Which of these refers to mechanics?
a. punctuation
b. spelling
c. capitalization

The correct answers is: All of the above.

Explanation:

I know you didn’t include this option, however, let me tell you that ‘mechanics’ refers to each one of these options you’ve mentioned: punctuation, spelling and capitalization; in difference with grammar as this one focuses on the parts of speech and how they combine together to form sentences. In this context, both -mechanics and grammar- are an essential requirement to clearly communicate your written ideas.

All of the above (if its not an options its either a or c)

explantion:

mechanics includes punctuation, capitalization and paragraphs

its hard for me to see which word is supposed to be in bold. if i knew then i would be able to better.