Выбрать вариант ответа в Past Simple: My parents ______ fresh lemonade an hour ago

The sentence requires the past simple tense. The negative form of the past simple is formed with 'did not' (didn't) + base form of the verb. Therefore, 'didn't drank' is grammatically incorrect as 'drank' is the past tense form. The correct option is 'didn't drink'.