The answer is B. Dead zone
Dead zones refer to the water territories which have little or no maritime life do lack of oxygen in the water
Since fish other maritime lives breath using the oxygen that is contained in the water, they won't be able to live in a water territory that have anoxia
The Respiratory System brings oxygen into the blood; it is the responsibility of the Circulatory System to transport it, with nutrients from digestion, to cells of the body.
The Circulatory System is three-fold: the blood carrying the substances, the vessels in which blood flows, and the heart which pumps it around in a circle-like movement and back (hence the term 'circulatory').
