Fact 1: Adult tunicates are barrel-shaped.

Fact 2: Urochordates are commonly called tunicates.

Given the two facts above, answer the question "Adult urochordates are _-shaped." with the following options: 
- Length
 - a prism
 - fossils
 - grow
 - barrel
 - fertile
 - Grow well
 - revolving


 

     barrel    