$50.0\mathrm{mL}$ of $0.100\mathrm{M}$ acetic acid ($K_a=1.8\times 10^{-5}$) is titrated with $0.100\mathrm{M}$ NaOH. The steep part of the curve extends from the point $99.9\%$ neutralised to the point $0.1\%$ past equivalence. Take it as: lower limit by $\mathrm{pH}=\mathrm{p}{K}_a+\log (99.9/0.1)$ and upper limit from the excess $\mathrm{OH}{}^{-}$ in about $100\mathrm{mL}$. An indicator is suitable if its $\mathrm{p}{K}_{in}$ lies within this jump. Which statements are correct?

1. AThe lower limit of the jump is pH $=7.74$.
2. BThe upper limit of the jump is pH $=9.70$.
3. CPhenolphthalein ($\mathrm{p}{K}_{in}\approx 9.3$) and thymol blue (basic range, $\mathrm{p}{K}_{in}\approx 8.9$) are both suitable.
4. DBromothymol blue ($\mathrm{p}{K}_{in}\approx 7.0$) is suitable.