I haven't talked to him ___ last week.
-
For
-
After
-
Since
-
None of these
C
Correct answer
Explanation
The word 'since' is used to mark the beginning of a period that continues to the present. 'Last week' is a specific point in time, which requires 'since' in the present perfect tense. 'For' is incorrect because 'last week' is not a duration.