In this question, we have some mathematical relations for the ages of a father and his son.

In option 1, if the son was 16 years old in 1940, then he would have been 6 in 1930 and the father 48 in 1930. Eight years later, the father would be 56, which is not ten times the son`s age in 1930, so option 1 is incorrect.

Option 2 suggests the son was 15 in 1940, which means he was 5 in 1930 and the father 40. Eight years later, the father would be 48, again not ten times the son`s age in 1930, so option 2 is incorrect.

Option 3, the correct answer, puts the son at 14 in 1940, making him 4 in 1930 and the father 32. Eight years later, the father would be 40, exactly ten times the son`s age in 1930.

Option 4 with the son at 13 in 1940, 3 in 1930, and the father 24, doesn`t fit the equation as eight years later the father is 32 not ten times the son