Phenolphthalein does not act as an indicator for the titration between

Phenolphthalein is the most suitable indicator for the titration of:

Which indicator is used for the titration of a weak acid (oxalic acid) and a strong base (caustic soda)?

The best indicator for the detection of the end point in the titration of a weak acid and a strong base is:

Which indicator can be used in the titration of a strong acid and a strong base?

The titration curve of a weak acid vs. a strong base with phenolphthalein as an indicator is shown below. The $K_{In} = 4 \times 10^{-10}$. Given: $\log 2 = 0.3$. The number of the following statements which is/are correct about phenolphthalein is $.....$.
$A$. It can be used as an indicator for the titration of a weak acid with a weak base.
$B$. It begins to change colour at $pH = 8.4$.
$C$. It is a weak organic base.
$D$. It is colourless in an acidic medium.