There are choices for this question namely:
1. Pregnancy
2. Renal failure
3. Prolonged QT interval
4. Adverse reaction to levothyroxine
The correct answer is "pregnancy". Methimazole is a potent teratogenic drug which means Methimazole readily crosses the blood-placenta barrier and affect the baby adversely such that it can lower the fetus' thyroid hormone levels and cause cretinism for instance. An adverse reaction to levothyroxine is inappropriate to assess because levothyroxine is a drug for hypothyroidism, not for hyperthyroidism. Methimazole is not associated with prolonged QT interval and renal failure.