Answer:
A
Explanation:
In this question, we are to select amongst the options which is the correct reason why the experiment conducted was not blind.
Now when they say an experiment is blind, it means certain conditions that surround the carrying out of the experiment was unclear to the participants of the experiment.
Now, we need to state the reason why the experiment was not blind. The experiment is said to be blinded if it is that the students were unaware of the color with which the room was painted. Since, it is impossible to blind the color of the paint of the exam room students will be aware of the color of the paint. Hence, they are not blinded.
This makes option A the correct answer