A weak-acid indicator HIn has $K_{In}=1.0\times 10^{-5}$. Assume the acid colour is seen when $[\mathrm{HIn}]/[\mathrm{In}{}^{-}]\ge 10$ and the base colour when $[\mathrm{In}{}^{-}]/[\mathrm{HIn}]\ge 10$. Select the correct statements.

1. AAt pH 5.0 the two forms are present in equal amounts
2. BThe pure acid colour is seen at pH 4.0 or lower
3. CThe colour change range is about pH 4 to pH 6
4. DAt pH 3.0 the ratio $[\mathrm{In}{}^{-}]/[\mathrm{HIn}]$ is 0.1