Which sentence includes a dependent clause?
She smiled as she opened the package.
Today is her 16th birthday.
It was a fancy hat!
The package was heavy.
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.