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

Input:
I'm going to return mine ... this unit locks up regularly due to overheating problems...The bios upgrade didn't fix anything... leaving a desktop fan blowing over the unit does.
Also the battery life is horrible... under 2 hours for regular use.
Nice speakers and seems fast enough when running.

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