Answer: The correct answer is option(A).
Step-by-step explanation:
Litmus paper is used to test whether given solution is acidic or basic(alkaline).
There are two types of litmus paper:
1) Blue Litmus paper: The color of this litmus paper is blue, when treated with acid it turns red and when treated with base it remains blue.
2) Red Litmus paper:The color of this litmus paper is red, when treated with acid it remains red and when treated with base it turns blue.
Since, the substance in beaker did not change the color of blue litmus paper which means that it is a base.