According to yor reading material which of the following would not be deleted or replaced when editing your essay for more concise writing

When a writer edits his/her own work, all four errors in grammar and usage listed above, need to be looked for.
a. Ways to replace overused words.  A paragraph sounds clumsy when the same words are used too many times in a sentence/paragraph
b. Problems with verb tenses. It is very important to use the same verb tense throughout your written work. 
c. Sentences missing commas and periods. If a sentence does not contain commas and periods, it is confusing and ends up being a jumble of words. 
d. Misused or missing capitalization.