A stage in writing where you look for any mechanical errors is e. Editing.
Explanation:
<u>Editing</u> is a stage in the writing process the author or editor uses to make corrections on a draft. This correction includes looking for mechanical errors, making sentences more effective and clearer, and adding, deleting or rearranging what is necessary. All these factors are important, since many times the <u>editing stage</u> is the moment used to prepare the writing for its publication.