Answer: d. insulin
<span>Actually, there are two hormones secreted by islet cells within the pancreas: insulin and the glucagon. However, their secretions in response to blood sugar levels, are in opposite fashion! </span>
<span>Insulin is normally secreted by the beta cells of the pancreas while glucagon by the alpha cells. The </span><span>amount of insulin secreted into the blood increases as the blood glucose rises. In the same way, as the blood glucose falls, the amount of insulin secreted by the pancreas goes down.</span>
In glucagon, it is opposite. If blood glucose is high, then there is no glucagon secreted. Therefore, the answer is insulin.
<span>Pregnancy tests detect Human Chorionic Gonadotropin, or HCG, that can be found in a pregnant woman's urine. Human Chorionic Gonadotropin is secreted by the embryo and serves to maintain the corpus luteum and the production of estrogen and progesterone.</span>
B because a and c are incorrect and in letter d it states earth has no protection at all. And it DOES have protection B is most definitely true
