B
Below is a question with multiple-choice answers. Choose the correct option based on your reasoning.

### Question:
What is the frequency of ocean waves that have a speed of 18 m/s and a wavelength of 50 m?

### Choices:
A. 0.18 Hz
B. 0.36 Hz
C. 2.8 Hz
D. 9.0 Hz

### Answer:
