Variable a is 4 more than variable b. Variable a is also 1 less than b. Which of the following pairs of equations best models the relationship between a and b?
(4 points)
A a = b + 4 a = b – 1
B a = 4b a = b + 1
C b = a + 4 b = a – 1
D b = 4a b = a + 1