Answer:
a. A chilly examination room or your cold hands have activated the cremasteric reflex.
Step-by-step explanation:
Cremasteric reflex is the superficial reflex which is found only in human males that is revoked when inner thigh is stroked. Stroking the skin activates the cremaster muscle and it helps to contract ipsilateral testicle up towards the inguinal canal.
Thus in the context, in the preschool exam, the examiner could not feel the baby's testes but his parents claims that the testes are visible while having bath and are normal in size. The examiner could not palpate the baby's testes because the the room was cold enough or the examiner's hand was cold enough which activated the cremasteric reflex and it makes the testes to pull up.
Hence the correct option is (a).