Maybe this helps:
Conjugation of 'Sing'
Base Form (Infinitive): Sing
Past Simple: Sang
<em><u>Answer:</u></em>
b) The comma attempts to join two independent clauses.
<em><u>Explanation:</u></em>
When two ideas come together and either one of them can stand by itself as its own, independent sentence, then the use of the comma is correct:
Comma + a conjunction (and, but, for, nor, yet, or, so)
North Atlantic treaty organization
Iambic pentameter. hope that helps