11) B

Increasing the rotating speed, amplitude will get larger and frequency will increase (more rotations per second).

Let us say initial amplitude is 1 (1 box up from midpoint to crest)  and frequency is 3 (3 waves shown).

A – frequency increases but amplitude remains the same. This is wrong.

B – frequency increases and amplitude increases. This is correct.

C – Amplitude remains the same. Frequency decreases. This is wrong.

D – Amplitude increases. Frequency decreases. Wrong.

E – Amplitude increases but frequency remains the same. Wrong.