A student adds a few drops of the universal indicator to a solution of dilute hydrochloric acid. He would observe that the color of the solution changes from colorless to:

A universal indicator is a pH indicator composed of a solution of several compounds that shows several smooth color changes in the range of pH values ​​from 0 to 14 (can be negative or higher depending on concentration) to indicate the acidity or alkalinity of solutions, where 7 means neutral.

Now, acids are substances that are capable of releasing hydrogen ions in the solution while bases liberate hydroxide ions in the solution.

It shows red color if the solution is acidic and blue-violet color if the solution is basic.

Now, a dilute hydrochloric acid releases hydrogen ions into the solution and thus it is an acidic substance and hence shows red color when a universal indicator is added to it.

Hence, the correct option is (A).