Consider the following Statement (S) and Reason (R)
  S: Both sinx, cosx are decreasing functions in the interval 
  R: If a differentiable function decreases in an interval (a, b) then the derivative also decreases in (a, b)
  Which of the following is true?
 a)    Both S and R are wrong
  b)   Both S and R are correct but R is not the correct explanation of S
  c)    S is correct and R is the correct explanation of S
  d)   S is correct and R is wrong