Which of the Following Sentences Is Correct

Which of the following sentences is correct?

A) The greater the number of independent variables measured, the easier it is to interpret higher-order interactions.
B) The greater the number of independent variables measured, the more difficult it is to interpret higher-order interactions.
C) The greater the number of independent variables measured, the more difficult it is to interpret the lowest-order interaction(s) .
D) The greater the number of independent variables measured, the easier it is to interpret the lowest-order interaction(s) .