<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:An investigator is studying obesity in mice. Over the course of 2 weeks, mice in the experimental group receive a daily injection with a synthetic analog of an endogenous hormone. Compared to the control group, the hormone-injected mice eat more and gain significantly more weight. Which of the following is the most likely explanation for the observed weight gain in the experimental group?? A: Cholecystokinin stimulation of the nucleus tractus solitarius, B: Somatostatin inhibition of the anterior pituitary, C: Leptin stimulation of the ventromedial hypothalamus, D: Ghrelin stimulation of the lateral hypothalamus, E: Glucagon stimulation of hepatocytes,  <response>: This is a question about the effects of hormones on appetite and weight gain in mice. The experimental group was injected with an analog of an endogenous hormone and gained more weight than the control group. This means the hormone likely increased appetite and food intake. Of the choices given, ghrelin is known to stimulate appetite by acting on the lateral hypothalamus. The other hormones given either decrease appetite leptin, cholecystokinin or are not known to directly affect feeding behavior somatostatin, glucagon. Therefore, the most likely explanation is that the injected hormone is a ghrelin analog that stimulated feeding behavior by acting on the lateral hypothalamus.D: Ghrelin stimulation of the lateral hypothalamus 