Dr. Slotsky is a well-liked professor. Last term, no one received less than a B in any of his courses. Dr. Slotsky may be suffering from perceptual error.

The question is incomplete as it does not have the option which are:

1. Halo

2. Leniency

3. Central tendency

4. Recency

Leniency

Explanation:

A perceptual error is a phenomenon which occurs when the person holds some preconceived ideas about some other person on the basis of which the person is not able to make accurate perceptions about the person.

In the given question since the Dr. has not given less than B grade, this could be the result of the Halo type of perceptual error in which the person assumes that one parameter can be responsible for all other parameters and the person make incorrect errors like he could have considered attendance as a parameter ad on the basis of that he could have become more lenient towards the student with full attendance.

Thus, Leniency is the correct answer.

substitution is the answer in this case