Which of the following describes a simple sentence?

Question

A sentence that contains one independent clause and at least one dependent clause
A sentence that contains two or more independent clauses that are usually joined with a comma and a conjunction
A sentence that contains two independent clauses and at least one dependent clause
A sentence that contains a sentence that contains a subject and a verb and expresses a complete thought

Answer 1

A sentence that contains a subject and a verb and expresses a complete thought.