Choose the group of words that forms a complete sentence.

• A. We're off!
• B. Wind, fire, water—elements of the Earth.
• C. Helps us save money on car insurance and fuel costs.
• D. My neck of the woods.

Answer: (A)

The key idea here is recognizing a complete sentence as a group of words that expresses a full thought with a subject and a finite verb, able to stand on its own. “We’re off!” does that: the subject is “we,” the finite verb is the contracted form “we’re” (we are), and “off” completes the meaning, giving a full idea that the group has started or departed. The other phrases don’t form complete sentences because they lack a finite verb to express a complete action or state: “Wind, fire, water—elements of the Earth” is a noun phrase listing items; “Helps us save money on car insurance and fuel costs” misses a clear subject performing the action; “My neck of the woods” is another noun phrase referring to a place. So the sentence that fits the requirement is the one with a subject and a complete predicate: “We’re off!”