<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:In an attempt to create other selective dopamine 1 D1 agonists, a small pharmaceutical company created a cell-based chemical screen that involved three modified receptors - alpha 1 A1, beta 1 B1, and D1. In the presence of D1 stimulation, the cell would produce an mRNA that codes for a fluorescent protein; however, if the A1 or B1 receptors are also stimulated at the same time, the cells would degrade the mRNA of the fluorescent protein thereby preventing it from being produced. Which of the following would best serve as a positive control for this experiment?? A: Bromocriptine, B: Dobutamine, C: Dopamine, D: Epinephrine, E: Fenoldopam,  <response>: This is a question about selecting an appropriate positive control for a cell-based chemical screen involving three modified receptors - alpha 1 A1, beta 1 B1, and dopamine 1 D1. The goal is to identify compounds that selectively stimulate the D1 receptor. The positive control should activate the D1 receptor without stimulating A1 or B1. Bromocriptine A is a D2 receptor agonist, so it would not be expected to activate D1. Dobutamine B is a beta-1 adrenergic agonist, so it would activate B1. Dopamine C is a nonselective dopamine receptor agonist that would activate D1 but likely also A1 and B1. Epinephrine D is a nonselective adrenergic receptor agonist that would activate A1 and B1 but not D1. Fenoldopam E is a selective D1 receptor agonist. It would be expected to stimulate D1 without activating A1 or B1. Therefore, fenoldopam would be the best positive control for this experiment.E: Fenoldopam 