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

Input:
1) the first one arrived without the bolts necessary to put it together safely
2) I called the company and they replied promptly, telling me that they do not ship parts, only whole trampoline boxes.  So they did and it came promptly.  (doesn't seem cost-efficient to me, but I don't run the company...)
3) I put together the second one, and after a few bounces by my 5 and 11 year old grandchildren, the frame warped so that it no longer sat evenly on the ground.  Haven't tried fixing it yet, but am wondering whether it's safe at all.
4) Note that this is described as an exercise trampoline (presumably for adults) - when the 11 year old jumped on it, he commented that it is too firm (he's a trampoline maven)... so I don't know if this means it isn't good for kids at all, or whether he just prefers jumping on the sofa...!

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