Instruction: Given the user's review, identify the user's sentiment from the listed options. Answer using one of the options.

Input:
This therm-a-seat is just ok. It's ok for sitting short periods of time. It doesn't keep as warm as I would of expected and I should have made sure that it was thicker.

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