The Rejection Region for Testing the Hypotheses $H _ { 0 } : \mu =$

Multiple Choice

The rejection region for testing the hypotheses $H _ { 0 } : \mu =$ 80. $H _ { 1 } : \mu$ < 80. at the 0.10 level of significance is:

A) z > 1.96.
B) z < 0.90.
C) z > -1.65.
D) z < -1.28.