For the two reactions I : A $\to$B; II: C$\to$D following graph is obtained. 

Which of the following is true:

(1) True 

                         A          $\to$          B

Initial             0.5                          0

At eq.            0.25                        0.25

When [A] = [B] = 0.25 M

$\begin{array}{l}[B{]}_t=k_{1}t=\tan {30}^{\circ }t=\frac{1}{\sqrt{3}}t\\ 0.25=\frac{1}{\sqrt{3}}t,\therefore t=0.25\sqrt{3}.\\ [\mathrm{D}{]}_t=k_{\mathrm{II}}t=\tan {60}^{\circ }t=\sqrt{3}t(t=0.25\sqrt{3}\cdot )\\ =\sqrt{3}\times 0.25\times \sqrt{3}\\ =0.75\mathrm{M}.\end{array}$

(2) False 

if [C] = [A] then at that time [B] < [D]

(3) False

$\begin{array}{l}{t}_{100\mathrm{\%}}=\frac{a}{k}\left(\text{ for zero order }\right)\\ k_{\mathrm{I}}=1/\sqrt{3},k_{\mathrm{II}}=\sqrt{3}\\ \frac{\left(t_{100\mathrm{\%}}\right)}{\left(t_{100\mathrm{\%}}\right)}=\frac{a_{\mathrm{I}}}{a_{\mathrm{II}}}\cdot \frac{k_{\mathrm{II}}}{k_{\mathrm{I}}}=\frac{0.5}{1}\times \frac{\sqrt{3}}{1/\sqrt{3}}=\frac{3}{2}\end{array}$

(4) $[\mathrm{A}{]}_t=[\mathrm{A}{]}_0-k_{\mathrm{I}}t\text{ or }[A{]}_t=0.5-\frac{1}{\sqrt{3}}t$

$$\begin{gathered} [\mathrm{C}{]}_{\mathrm{t}}=[\mathrm{C}{]}_0-{\mathrm{k}}_{\mathrm{II}}\mathrm{t}\text{ or }[\mathrm{C}{]}_{\mathrm{t}}=1-\sqrt{3}\mathrm{t} \\ \mathrm{if} [.4]=[\mathrm{C}{]}_{\mathrm{t}} \end{gathered}$$

$\begin{array}{l}\text{ i.e., }0.5-\frac{1}{\sqrt{3}}t=1-\sqrt{3}t\\ \text{ or }\left(\sqrt{3}-\frac{1}{\sqrt{3}}\right)t=0.5\\ t=\frac{\sqrt{3}}{4}min.\end{array}$