A solution turns Phenolphthalein indicator pink. The most likely pH of the solution will be: (a) 6 (b) 4 (c) 9 (d) 7

Option (c) is the answer. Phenolphthalein is the indicator used in acid-base titration in order to identify whether solution is acid or base. Here the indicator shows colourless to pink indicates that the medium is basic and pH is 10 which is greater than 7