If July 15 of the year 2012 was Sunday, what was the day on July 15 of the year 2008 ?

The correct answer is (d).

The day of the week repeats itself every 7 days. Therefore, if July 15 of the year 2012 was Sunday, then July 15 of the year 2008 was also Sunday.

Option (a) is incorrect because Monday is 1 day after Sunday.

Option (b) is incorrect because Tuesday is 2 days after Sunday.

Option (c) is incorrect because Friday is 4 days after Sunday.