They prey on human emotion
Marta is the subject of the sentence because she is performing the verb "Planned"
I think it's D because A is correct B could be right and C is wrong. But the answer D is basically A and B combined. I know i explained that horribly but D should be correct.
Most likely, Mayra will develop heart-related problems when she grows older. Most heart problems, especially high blood-pressure, are hereditary, meaning that she will most likely develop a form of these problems at some point in her life. She is also much more likely to have a heart attack in her life.
The answer to this question is A!