The detective had a lot of corporeal evidence to sort through, unfortunately the bulk of it would prove to be what?
Options:
- intangible
- spiritual
- transparent
- ethereal
- insubstantial
Let's think carefully first. Step-by-step reasoning process:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Insubstantial means not being sufficient. When a corporeal evidence is unfortunate that means it is not sufficient. So the final answer is insubstantial.