I visited my aunt just before a week.

Options

A. a week before
B. a week earlier
C. a week ago
D. No Improvement

Answer

C

Explanation

(3) ago (Adv.) : used in expressions of time with the Simple Past Tense to show how far in the past something happened
before (Adv.) : at an earlier time , in the past • the week before (the previous week)
• long before (a long time earlier)
earlier (Adv.) : near the beginning of a period of time, an event, a piece of work, etc.
• early in the week /year/season/morning
Here, a week ago is the right usage.