The correct option is A 7.7
60 is in between two perfect squares: 49, which is 72 and 64 which is 82. The difference between 64 and 49 is 15 so 60 is little more than 23 of the way toward 64 from 49. A reasonable estimate for √60, then would be about 7.7 which is a little more than 23 toward 8 from 7.