The untreated sewage discharged by cruise ships is
a.
blackwater
b.
greywater
c.
solid waste
d.
not considered pollution

Untreated sewage discharged into the ocean by cruise ships causes a great amount of pollution into ocean biospheres.  It contains solid and liquid waste from the ships toilets and is very unsanitary.  It is not only harmful to the fish but also to humans in the area. It is given the title blackwater because it is not something that can be easily reused and should not be discarded into the oceans or other aquatic locations.

Hydrosphere is the correct answer