Final answer:
The best indicator for titrating a strong base with a strong acid in this scenario is phenolphthalein, as it has a pKin value close to the expected pH at the equivalence point and shows a clear color change.
Step-by-step explanation:
The best indicator to use for titrating a strong base with a strong acid when the equivalence point (Veq) is around pH 3 and the end point occurs at around pH 11 is phenolphthalein (option B, pH range 8.2 - 10). This is because an indicator chosen for a titration should have a pKin value close to the expected pH at the equivalence point. With the steep pH change that occurs near the equivalence point in a strong acid-strong base titration, indicators with a pH transition range near the equivalence point will efficiently signal the endpoint. Phenolphthalein, with a pKin of 9.5, will show a clear color change at the end of the titration, making it a reliable choice. Methyl red and bromthymol blue are more suitable for titrations involving weak acids and weak bases, respectively, due to their lower pKin values. Phenolphthalein will change from colorless to pink near the equivalence point, indicating completion of the titration effectively.