The correct options are
A Insulin
D Glucagon
Insulin and Glucagon.
Insulin and glucagon are hormones secreted by islet cells within the pancreas. They are both secreted in response to blood sugar levels, but in opposite fashion. Insulin is normally secreted by the beta cells (a type of islet cell) of the pancreas. The stimulus for insulin secretion is a HIGH blood glucose it's as simple as that.
Glucagon is secreted by the alpha cells of the pancreatic islets in much the same manner as insulin except in the opposite direction. If blood glucose is high, then no glucagon is secreted.