Which of the following sentences contains a capitalization error? (5 points) 1)the president and his family visited some historic sites. 2)the family of president jones enjoyed a vacation. 3)the nation looks to the president for leadership. 4)the media interviews the president most days.

The correct answer is 2) The family of president Jones enjoyed a vacation. 
When it comes to government positions, when they are located in front of a person's name, they are always capitalized. So here, the word President should be capitalized. You shouldn't change anything in the other options - they are correct as they are.