$\mathrm{A}\to \mathrm{B},{\mathrm{K}}_1=0.693{\sec }^{-1};\mathrm{C}\to \mathrm{D},{\mathrm{K}}_2=0.693$${\min }^{-1}$. If ${\mathrm{t}}_1$ and ${\mathrm{t}}_2$ are half lives of two reactions, then

$\begin{array}{rl} & {\mathrm{t}}_{1/2}=\frac{0.693}{\mathrm{K}}\\ & \frac{{\mathrm{t}}_1}{{\mathrm{t}}_2}=\frac{{\mathrm{K}}_2}{{\mathrm{K}}_1}\\ & {\mathrm{K}}_1=0.693{\sec }^{-1}\text{and}{\mathrm{K}}_2=\frac{0.693}{60}{\sec }^{-1}\\ & \text{As,}1\min =60\sec \\ & \frac{{\mathrm{t}}_1}{{\mathrm{t}}_2}=\frac{0.693/60}{0.693}\\ & {\mathrm{t}}_2=60{\mathrm{t}}_1\end{array}$

Therefore, the correct option is (D).