Aheart is to muscle as the stomach is to a tendon; ligament b involuntary; ligament c skeletal; smooth d cardiac; smooth

Cardiac muscle also known as heart muscle is one of three kinds of vertebrate muscles. It is a striated and an involuntary muscle, which forms the prime tissue of the walls of the heart. The cardiac muscles help in contraction of heart to pump blood.  

On the other hand, the smooth muscle is found inside the walls of the internal organs and the compositions like the stomach. The stomach has three layers of smooth muscles, that is, the outer longitudinal, the middle circular, and the inner oblique muscles.  

Therefore, the heart is to cardiac muscles, and the stomach is to smooth muscles.  

this is more of a statement than a question. is there answers to go along with this, or is it opinion based?

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.