Methyl orange gives $.......$ color in an acidic medium.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Phenolphthalein is a $pH$ dependent indicator,remains colourless in acidic solution and gives pink colour in basic medium.
Reason $R$: Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.
In the light of the above statements,choose the most appropriate answer from the options given below.

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

In base $vs.$ acid titration,at the end point,methyl orange is present as:

Phenolphthalein is the most suitable indicator for the titration of:

In an acid-base titration,the rapid change in $pH$ near the equivalence point depends on the indicator used. The $pH$ of the solution is related to the ratio of the concentrations of the conjugate acid $(HIn)$ and base $(In^-)$ forms of the indicator by which equation?