Answer:
The correct option is B.
Explanation:
Muscle tissues of the heart refers to a group of cells that are carrying out similar functions in the heart. There are three different types of muscles, these are skeletal, cardiac and smooth muscles. The cardiac muscles are found in the heart, they form the contractile wall of the heart. These muscle contract involuntarily ( that is, without any external stimulation) and they are single nucleus, striated and short. 
 
        
                    
             
        
        
        
The answer is tunicates. Tunicates are commonly known as sea squirts and are in the Chordata phylum, even though they don't have a back bone. Which is really weird. But they just got put into the same category as humans. This is because they have a notocord and a back bone when they are larvae. But they lose all these when they become adults.
        
                    
             
        
        
        
Answer: 2,000 miles.
Explanation:
The Aleutian Trench, which has formed along the convergent boundary and has been produced by the subduction of the oceanic plate, extends for 2,000 miles.
 
        
             
        
        
        
Answer:
A
Explanation:
I know this because I just took the test and got it right.
 
        
                    
             
        
        
        
It is called a 'response'.
<em>Hope this helped! :)</em>