Instruction: Assess the user's sentiment in the provided review and select the appropriate sentiment option from the list as the answer.

Input:
Not sure what more you can expect from a transistor plug in. They ROCK! From an old guy that replaced an old crummy pair, there is power to burn. Don't take my word for it though, I just got back from the AC/DC last week.

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