Answer: F
Critical regions get smaller as α-values get smaller.
Step-by-step explanation:
The figure below shows the critical regions (shaded) for a 2-tailed test at the 95% confidence level.
Because the total area under the curve is 1, the α-value is 1 - 0.95 = 0.05.
It is split up into 0.025 for a two-tailed test. It remains at 0.05 for a one-tailed test.
The critical z-score at 95% confidence level is z* = 1.96.
When the α-value decreases:
(a) the z* value increases,
(b) the confidence level increases,
(c) the critical region decreases.