Answer:
The kind of error that occurs is:
B. a pronoun shift error.
Explanation:
Take a look at the following sentence:
"One could have done better if we had studied harder."
See how the sentence begins by using "one" and then suddenly shifts to "we"? This is an example of a pronoun shift error. The pronoun "we" does not agree with "one".
Let's analyze another example:
"Someone is knocking; and they seem to be in a hurry."
Although that is a common structure in colloquial speech, it is incorrect. "Someone" is a third-person singular word, so the pronouns that refer to it should be "he" or "she". "They" is a third-person plural pronoun. Therefore, this example too shows a pronoun shift error.
Because they believe Sirius Black is there.
