There typically are tradeoffs when selecting a solution to a problem. Genetically engineered crops may be able to help farmers produce greater yields, but a tradeoff is the reduction in the genetic variation in crops, making crops more susceptible to disease. What other tradeoffs exist for this solution?

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

the answer is c because it is most logical.