The subtidal zone is the area: Between low and high tide. Beyond the continental shelf.
Between the intertidal zone and the edge of the continental shelf.
Where pelagic organisms live.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.

then go eat. lol.brainliest