Answer:
The correct answers is: All of the above.
Step-by-step 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.