The correct option is D Punishment to the Macdonald clan would set an example to the other Highland clans
King William III wanted all Scottish clans to swear allegiance to him before the New Year's Day of 1691. The chief of the MacDonald clan, Maclain MacDonald, could not make his oath in front of King William III before the given time. William III decided to punish the MacDonald clan to set an example to the other Highland clans. In order to do that, he ordered 120 soldiers to be placed in the homes of the MacDonald clan in Glencoe.
Thus, option C is correct.