Q: Adult urochordates are _-shaped.
Options:
- (A) Length
- (B) a prism
- (C) fossils
- (D) grow
- (E) barrel
- (F) fertile
- (G) Grow well
- (H) revolving
A: (E)
Explain how we arrive at this answer:

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
Explanation: Adult tunicates are barrel-shaped. Urochordates are commonly called tunicates. Adult urochordates are barrel-shaped.