Seagrass Beds Extend Along Much of the Atlantic Coast of the United

Seagrass beds extend along much of the Atlantic coast of the United States.A group of scientists is studying an estuary that contains seagrass beds.They arbitrarily set a boundary around their study community such that it includes a 100-yard length of seagrass plus the next 100 feet of water extending from it in all directions.Are the scientists defining their community in theoretical or practical terms?

A) Theoretical, because they are measuring it
B) Theoretical, because their boundary is arbitrary
C) Theoretical, because their boundary includes the whole community
D) Practical, because they include a manageable portion of the community
E) Practical, because their boundary is arbitrary