\(\,\quad\quad\quad\quad2s\quad\quad\quad3s\)
\(k _{ sp } =(2 s )^{2}(3 s )^{3}\)
\(=4 s ^{2} \times 27( s )^{3}\)
\(=108( s )^{5}\)
\(( s )^{5} =\frac{1.08 \times 10^{-73}}{108}\)
\(\Rightarrow s =10^{-15}\)
$(A)$ $0.01 \,M\, HCl$
$(B)$ $0.01 \,M \,NaOH$
$(C)$ $0.01 \,M \,CH _{3} COONa$
$(D)$ $0.01 \,M \,NaCl$