Final answer:
The finding that would indicate that a child had a tonic-clonic seizure during the night is when the child has bitten the tongue.
Step-by-step explanation:
The finding that would indicate that a child had a tonic-clonic seizure during the night is c. The child has bitten the tongue.
During a tonic-clonic seizure, also known as a grand mal seizure, the muscles in the body contract and relax rapidly, causing the child to experience convulsions. Biting the tongue is a common consequence of the intense movement during a seizure.