What is a complex sentence?

A: a sentence that contains two or more independent clauses joined by a subordinating conjunction
B: a sentence that contains an independent clause and at least one dependent clause joined by a subordinating conjunction
C: a sentence that contains an independent clause and at least one dependent clause joined by a subordinating conjunction
D: a sentence that contains two or more independent clauses joined by a subordinating conjunction

B: a sentence that contains an independent clause and at least one dependent clause joined by a subordinating conjunction