Concept:Subject-verb agreement and the correct use of correlative conjunctions decide the erroneous parts.
Explanation:In part (B), the verb "include" is plural.
The subject "The United Kingdom" is singular.
A singular subject must take a singular verb.
Therefore, the correct verb form is "includes".
So part (B) is incorrect.
In part (D), "either" is incorrectly paired with "and".
The conjunction "either" must be used with "or" to show a choice.
The correct phrase should be "either Great Britain or Ireland".
So part (D) is also incorrect.
Parts (A) and (C) are grammatically correct.
The corrected sentence is: "The United Kingdom competes at the Olympics as Great Britain and includes athletes from England, Scotland, Wales, and those British Overseas Territories without their Olympic team, while athletes from Northern Ireland can choose to represent either Great Britain or Ireland."
Hence, only parts (B) and (D) contain errors.
Answer:Option (a) i.e. BD.