Which of the Following Describes the Main Reason for Using

Multiple Choice

Which of the following describes the main reason for using the deviation IQ formula instead of Stern's MA/CA × 100 formula to represent IQ scores?

A) Stern's formula underpredicts IQ scores for those under 20 years old.
B) Stern's formula is more difficult to calculate.
C) A 90-year-old would not likely be able to achieve an IQ of 100 using Stern's formula.
D) The older you are, the higher your IQ score will be according to Stern's formula.