What do you do to an irregular verb to put it in past tense

An irregular verb is one that does not form its simple past tense or its past participle by adding "-ed" or "-d" to the base form. Irregular verbs contrast with regular verbs, which form the simple past tense and past participle by adding "-ed" or "-d."

Explanation:

Since there are no specific rules regarding conjugating the tenses of irregular verbs, the only way to really learn them is to keep your ears open. Every time you learn a new verb, make sure you know all the conjugations of that verb so that when you use it you don't misspeak

i think that the answer would be d.