If a base is slowly added to an acidic solution, in which direction can the colour of universal indicator change?

Correct answer: From more acidic colours towards neutral colour

The governing concept is neutralisation and the corresponding movement of pH. An acidic solution initially has a pH below 7. As a base is added gradually, hydroxide ions react with hydrogen ions to form water, so acidity decreases and the pH moves toward 7. The universal-indicator colour can therefore shift from acidic colours, such as red or orange, toward green or another neutral colour. It may later become basic if excess base is added, but A correctly describes the initial direction.