In the following first order reactions : $A+ Regent \quad \underrightarrow{K_1} \quad product; \qquad B+ Reagent \quad \underrightarrow {K_2} \quad Product$ The ratio of $\large\frac{K_1}{K_2}$ when only $50 \%$ of B reacts in a given time when $94 \%$ of a has been reacted is :

Question

$(a)\;4.06 \\ (b)\;0.246 \\(c)\;2.06 \\(d)\;0.06 $