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

Input:
Koss PortaPro sound quality is sub-par in my estimation, not sharp and clear little mushy for me. I thought that with the Inclusion of Pro in the designation it would be of higher quality.

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