Instruction: Carefully assess the user's review for any strong expressions of sentiment, either positive or negative. Based on your analysis, select the most fitting sentiment option from the provided list as output.

Input:
I purchased the USB version of this unit and ran through the setup procedures without a hitch. When I started to use it , the trouble began. After many hours of frustration I called the technical support number and  was told by a rep and a supervisor that this device will not work if ANY  other USB device is used. This is unbelievable when you consider the entire  purpose of USB is to connect multiple devices to your computer! I was told  to disconnect my other USB devices (mouse, keyboard, scanner, printer, and  Palm Pilot cradle). When they saw the problem with disconnecting the mouse  and keyboard (duh), they told me to return it.

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