Scuba Divers Use a BCD to Control Buoyancy

Multiple Choice

Scuba divers use a BCD to control buoyancy.It is essentially a bag that can be inflated or deflated to prevent excessive sinking or floating.How do bony fish accomplish this?

A) They pump their operculum.
B) They adjust the level of gasses in their swim bladder.
C) They adjust their position using the pectoral and pelvic fins.
D) They swim rapidly to saturate the blood with oxygen.