Pink
blue
red
colourless
Answer is Right!
Answer is Wrong!
The correct answer is D. colourless.
Phenolphthalein is an indicator that is colorless in acidic solutions and pink in basic solutions. Vinegar is an acidic solution, so when phenolphthalein is added to vinegar, the solution remains colorless.
Option A is incorrect because phenolphthalein is colorless in acidic solutions.
Option B is incorrect because phenolphthalein is not blue in acidic solutions.
Option C is incorrect because phenolphthalein is not red in acidic solutions.