Answer:
B) As an anchor against tidal action
Explanation:
Byssal hairs (or threads) are used to anchor organisms to rocks and other solid surfaces to protect them from wave shock (tidal action).
These hairs/threads stretch out in many directions to hold the organism in place. Mussels are an example of an organism that uses byssal threads.
[This answer was pasted from another question I also answered. You can find it here: https://brainly.com/question/12319732 As I said, the original answer was also written by me.]
