Theory of acids and bases

Consider a $0.050\;M$ solution of the weak base pyridine ($C_5H_5N$ , $K_b$ $=$ $1.7 \cdot 10^{-4}$) $C_5H_5N$ $+$ $H_2O$ $HC_5H_5N^+$ $+$ $OH^-$

What are the changes in molar concentrations of each species ?

a) $+x\;M$, $-x\;M$, $-x\;M$ b) $-x\;M$, $-x\;M$, $+x\;M$ c) $-x\;M$, $-x\;M$, $-x\;M$ d) $-x\;M$, $+x\;M$, $+x\;M$