Equilibrium

Phosphoric acid ionises in three steps with ionisation constant values $K_{a_1}$, $K_{a_2}$ and $K_{a_3}$ respectively, while $K$ is the overall ionisation constant. Which of the following statements are true?

A. $\log K=\log K_{a_1}+\log K_{a_2}+\log K_{a_3}$

B. ${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4$ is a stronger acid than ${\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}$ and $\mathrm{HP}{\mathrm{O}}_4^{2-}$

C. $K_{a_1}>K_{a_2}>K_{a_3}$

D. $\frac{K_{a_2}+K_{a_3}}{K_{a_1}}=2$

Choose the correct answer from the options given below: