Instruction: Determine the sentiment expressed by the user in her review from the provided choices, and respond by selecting one of the available options.

Input:
Sound is fantastic.

The phones are light and comfortable, and the balance right to left is perfect.

Sound is very dynamic, and bass/midrange/treble balance is perfect.

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: A: very positive