Answer:
External
Step-by-step explanation:
An external attribution happens when the individual tends to attribute a situation or result to a situation that is outside their control and that depends on other person. In other words, they attribute it to external factors.
In this example, Juan failed his paper. He thinks the professor has unrealistic expectations and fails all his students regardless of their work. Juan is not even considering that it might be his own fault that he failed his test and he thinks it's the teacher's fault. Therefore he is attributing his grade to external factors and this is an example of external attribution.