English grammar error-spotting (correlative ‘‘neither … nor …’’ and proximity agreement): Read the sentence and choose the erroneous part; if none, pick ‘‘No error’’. Check subject–verb agreement with the nearest subject: ‘‘Neither he / nor his father is interested / in joining the party. / No error.’

Given data & grammar check

• Subject: ‘‘Neither he nor his father’’ → with ‘‘neither … nor …’’ the verb typically agrees with the nearest subject (here, ‘‘his father’’ → singular).
• Verb phrase: ‘‘is interested’’ → singular agreement is correct.
• Pronoun case: ‘‘he’’ (subjective case) is correct as part of a compound subject.

Result
All three parts A–C are grammatically sound; therefore, select No error.

Common pitfalls

• Changing ‘‘is’’ to ‘‘are’’ mistakenly.
• Using ‘‘him’’ instead of ‘‘he’’ in the subject.