Which sentence includes a dependent clause?

Question

She smiled as she opened the package.
Today is her 16th birthday.
It was a fancy hat!
The package was heavy.

Answer 1

The sentence that includes a dependent clause is:

"She smiled as she opened the package."

In this sentence, "as she opened the package" is the dependent clause because it cannot stand alone as a complete sentence and is dependent on the main independent clause "She smiled" for its meaning.