I believe for number 1 the answer is A 260
The right answer is D (less responsive to antigens)
It is proven that, after puberty, thymus activity (an organ that is included in the lymphatic system, producing T cells that pick up antigens) decreases and that in adult and aged people the thymus has no role. Work done in humans indicate that in fact the cellularity begins to decline from birth in favor of lymphocyte perivascular spaces and connective and adipose tissue, which leads to a decrease in the capture of antigens.
D surface tension because, adhesion is sticking, b makes no sense for this question, and heat has nothing to do with it either, because it distributes it's weight throughout its legs so it doesn't sink (it doesn't weigh much so this works.)
Hope this helps don't forget to hit that heart :)
