A paired difference experiment yielded $n_D$ pairs of observations. In each case described below, what is the rejection region for testing $H_0: \mu = 2$ against $H_a: \mu > 2$? Use $s_D = 11.9$.
(a) $\ $ $n_D = 34, \ \alpha = 0.08$

$z >$
(b) $\ $ $n_D = 28, \ \alpha = 0.06$

$t >$
(c) $\ $ $n_D = 8, \ \alpha = 0.08$

$t >$