Answer:
C. the mental age of 9.
Explanation:
The Binet's test is gotten by comparing the individuals mental age to his chronological age multiplied by 100. that is;
IQ = (mental age/chronological age) x 100.
Since Jarrod can do the work of a 9 year old, his mental age is 9 even though is chronological age is 7, and his IQ is calculated below'
IQ = (9/7) x 100
!Q = 129%.