Studies show that we may of what we hear.

a.10%

b.25%

c.30%

We remember about 20 percent of what we hear. So I suppose the closest answer to your text-book is the answer B (25)

When we hear something it is B.25% that we remember but if its written we remember 72% 

This is true. yes. indeed.

Bmust be the answer, as technically all organs move, so a is incorrect. all organs are made of different types of cells, so that isn’t a problem, so c is also incorrect. human hearts are very similar to many other animals’ hearts, so d is also incorrect, yet the heart is made of muscle, which is hard to grow in the lab so it would be correct to say b