I believe the correct answer is A , but I am not 100% sure , hope I helped (:
I believe List B lists causes of depression, although there are many causes of depression out there. B seems to be the best option though.
Ans. Contractility. It is defined as the intrinsic ability of the heart muscle to contract. An Anrep effect happens when there is an increase in contractility due to the activation of catecholamines. When this happens, it allows myocardium to compensate for an increase end-systolic volume and decreased stroke volume that occurs when aortic blood pressure increases.
gene density is about one gene per five kilo-base pairs. So I believe the answer is 20%