Answer:
The correct answer is - alkali or base.
Step-by-step explanation:
The litmus paper test is used to find whether a solution is basic or acidic. In a litmus paper test, a litmus paper is a dip in a particular or desired solution that turns the color of litmus paper to red, blue, or purple based on the pH of the solution.
If the paper turns red it means the solution is acidic, in a neutral solution it turns to the purple color and if the blue color appears then it is a basic or alkali solution. The solution of baking soda turns litmus paper into blue color which means baking soda is most likely a base.