Final answer:
False. Macroscopic biogenous sediment is not the most abundant in the marine environment.
Step-by-step explanation:
The correct answer is B. False. Macroscopic biogenous sediment refers to sediment that is derived from the remains of once-living organisms and is visible to eye. While biogenous sediment is indeed the most abundant in the marine environment, it is predominantly made up of microscopic organisms such as plankton, not macroscopic organisms.