The choice of indicator for an acid-base titration depends on the pH range at the equivalence point. - For a strong acid-strong base titration, the equivalence point is at pH 7, and indicators like bromoacid-weak base titration, the equivalence point is acidic (pH 7), and indicators like phenolphthalein suitable. Given the question asks for a strong acid and weak base, the equivalence point is acidic. Therefore, methyl orange is the most suitable indicator. However, if the provided correct answer is A) Phenolphthalein, it implies the titration is of a weak acid and a strong base, where the equivalence point is alkaline and phenolphthalein is the appropriate indicator. There appears to be a contradiction between the question and the intended correct answer.