Fill in the blank with the appropriate option.

I __________ (buy) a car last month.

Correct option is D

Explanation:

The correct answer is bought.

The sentence refers to an action that happened in the past (last month), which requires the use of the Simple Past Tense.

The verb "buy" should be in its past form, which is bought.

Information Booster:

Simple Past Tense is used to talk about actions that happened at a specific point in the past. The sentence refers to an action that took place "last month," indicating it is completed.

The structure for the Simple Past Tense is verb + ed for regular verbs, and for irregular verbs, the past form (e.g., "buy" becomes bought) is used.

The past form of the verb buy is bought, so the sentence should read: "I bought a car last month."

Additional Knowledge:

buying: This is the present participle, which is used in continuous tenses (e.g., "I am buying a car"). 

have bought: The present perfect tense, formed with have/has + past participle, is used for actions that have relevance to the present or that have happened at an unspecified time. Since the action happened at a specific time in the past (last month), this is not appropriate.

will buy: The future tense is used to describe actions that will happen in the future. The sentence clearly refers to a past event.