A compound sentence is a sentence that have at-least two independent clauses in it, meaning that these two clauses can be understood without the other clause also. These two independent clauses are joined either by conjunction with a comma or semi-colon, semi-colon, colon, dash, or by coordinating conjunction.
In the given examples, Option C is correct.
<em>"Max maintained that the database needed restructuring,..." </em>and <em>"and Laura agreed." </em>Both are independent clauses that can be understood without the other clause.
