What is a complex sentence?

A. A sentence with at least one independent and one dependent

clause

B. A sentence made up of two simple sentences joined together

C. A sentence that consists of only one independent clause

D. A sentence that states the author's personal opinion

A. A sentence with at least one independent and one dependent clause

Explanation:

A complex sentence combines a dependent clause with an independent clause. When the dependent clause is placed before the independent clause, the two clauses are divided by a comma; otherwise, no punctuation is necessary.

Example: Because the soup was too cold, I warmed it in the microwave.