Which of the following describes a simple sentence?

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

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