Sort the following words by the first letter of their spelling in the English alphabet.
Yahoo, Xanthum, Wolf, Zebra
Wolf, Xanthum, Yahoo, Zebra
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Sort the following words by the first letter of their spelling in the English alphabet.

### Response:
Wolf, Xanthum, Yahoo, Zebra