The sum of the current ages of a father and his son is 84 years. 7 years ago, father's age was 3 times the age of the son. After 7 years, son's age will be?

(A) 28 Years
(B) 35 Years
(C) 53 Years
(D) 58 Years

The sum of the current ages of a father and his son is 84 years. 7 years ago, father’s age was 3 times the age of the son. After 7 years, son’s age will be?