The question is incomplete as it does not have the option which are:
1. Halo
2. Leniency
3. Central tendency
4. Recency
Answer:
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.
Correct option - They have a crystalline structure.
The reason scientists believe this is that there was basically no oxygen in the atmosphere at this time, which meant that cells needed to be anaerobic to survive,<span> going around the problem of no oxygen in the atmosphere.
Hope this helps.</span>
