Choose the correct statements about the hydrides of group \( 15 \) elements.
A. The stability of the hydrides decreases in the order \( \mathrm{NH_3} > \mathrm{PH_3} > \mathrm{AsH_3} > \mathrm{SbH_3} > \mathrm{BiH_3} \).
B. The reducing ability of the hydride increases in the order \( \mathrm{NH_3} < \mathrm{PH_3} < \mathrm{AsH_3} < \mathrm{SbH_3} < \mathrm{BiH_3} \).
C. Among the hydrides, \( \mathrm{NH_3} \) is strong reducing agent while \( \mathrm{BiH_3} \) is mild reducing agent.
D. The basicity of the hydrides increases in the order \( \mathrm{NH_3} < \mathrm{PH_3} < \mathrm{AsH_3} < \mathrm{SbH_3} < \mathrm{BiH_3} \).
