Practice question
Question
Which amino acid is present at position 3 in vasopressin?
Explanation
Correct option is B, Phenylalanine. In Endocrinology, the accurate description is Phenylalanine, and that is what you should commit to memory. Keep the definition tight and the role clear — Phenylalanine is the option that correctly names the structure, process, or principle asked for in Endocrinology. Then Phenylalanine is the answer you can defend. Check yourself by covering the options and writing the answer first, then matching the letter — that builds confidence. If the wording feels dense, translate it into everyday language first, then map that plain sentence back onto Phenylalanine. Remember that physiology questions reward precise language: name the process, the location, and the outcome, then match that to the option text.