Which of the following drugs can cause rickets in children by interfering with Vitamin D action?

Correct Answer: C

Rationale: Phenytoin induces vitamin D metabolism, potentially causing rickets.

Correct Answer: D

Rationale: Vasopressin has all these roles: vasoconstriction (V1), neuromodulation, and factor VIII increase (V2).

Correct Answer: B

Rationale: Recombinant insulin may require less dose than animal insulin due to purity and potency. Allergic reactions are rare but possible, hypoglycaemia awareness varies, it can be given IV (regular form), and it's useful in type 2 diabetes.

Correct Answer: B

Rationale: Clomifene, a selective oestrogen receptor modulator, induces ovulation for infertility and increases multiple births. It raises FSH/LH and rarely causes psychosis.

Correct Answer: D

Rationale: All listed hormones are used diagnostically: CRH for adrenal, Cosyntropin for ACTH response, GnRH for pituitary-gonadal axis, TRH for thyroid function.