C i.e. Increases gastric emptyingExplanation:The Main Actions of GLP-1 are:Stimulate insulin secretion (i.e., to act as an incretin hormone). Limits postprandialInhibit glucagon secretion. glucose excursionsInhibits gastrointestinal motility and secretion.Thus, acts as an "enterogastrone" and a part of the "ileal brake" mechanism.(GLP-1 decreases gastrointestinal motility via direct inhibitory effects on muscle and also inhibits postprandial acid secretion).GLP-1 also appears to be a physiological regulator of appetite and food intake.It induces satiety, reduces food intake hence leading to reduced weight gain.Recent discovery: (b) is able to promote p-cell mass expansion.Hence, the correct option would be option (c).The properties of GLP-1 described above, including glucose-dependent stimulation of insulin secretion and expansion of [3-cell mass, coupled with the inhibition of glucagon secretion and food intake, suggest that it would greatly complement current [3-cell therapies.Also Note:Synthesis of GLP:Formed in L cells of lower GIT.Secreted as Preproglucagon.Human preproglucagon: Found in pancreatic A cells, in L cells in the lower gastrointestinal tract and brain.It is the product of a single mRNA, but it is processed differently in different tissues.Pancreatic A cells: Processed to glucagon, major proglucagon fragment (MPGF) and residual glicentin-related polypeptide (GRPP).Intestinal L cells: Processed to glicentin, glucagon-like polypeptides 1 and 2 (GLP-1 and GLP-2), residual glicentin-related polypeptide (GRPP) and some oxyntomodulin is also formed.Levels of GLP rise after food intake. Principally sugars and fats release GLP.