Fill in the blank (_) in the following sentence from the following choices.
Sentence: Paul set up the microscope and the hand lens for students to view the microorganisms, but the _ was the only one powerful enough.

Choice 1: Paul set up the microscope and the hand lens for students to view the microorganisms, but the lens was the only one powerful enough.
Choice 2: Paul set up the microscope and the hand lens for students to view the microorganisms, but the microscope was the only one powerful enough.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
2.