What is the purity of conc $H_2SO_4$ solution (specific gravity 1.8g/ml),if 5ml of this solution is neutralized by 84.6ml of $2.0N\;NaOH$

Question

$(a)\;93\%\qquad(b)\;91.5\%\qquad(c)\;92.12\%\qquad(d)\;94.6\%$