cholecystokinin is the answer, good luck!
Hmm, let me see. This illustration appears to be an image of a cell. But, there aren't any answers that has cell. Using logic, it would be an organelle. Mainly because there aren't any arrows directing to a specific organelle. Since a cell wall is an organelle, it has to be D.
If two different alleles for a trait are present and one allele doesn't entirely block the expression of the other, the genetic situation is in-complete Dominance