The concentration of $B(aq)$ will increase.
Work Step by Step
This is the equation for that equilibrium. $B(aq) + H_2O(l) \lt -- \gt HB^+(aq) + OH^-(aq)$ According to the Le Chatelier's principle, if we add $HB^+$ ions to the solution in equilibrium, it will try to consume these ions by shifting the equilibrium to the left. Which means that a larger quantity of $HB^+$ will be consumed, and a greater quantity of $B$ will be produced.