If the coefficient of the (3r)th term and the coefficient of the (r^2)th term in the expansion of (1 - x)^{2n} are equal, what condition must hold true?

a) r > 1 and n > 2
b) r < 1 and n < 2
c) r = 1 and n = 2
d) r > 1 or n > 2