Direction: In the following question, a part of the sentence is underlined.…

Concept

A phrase introduced by words such as "along with", "as well as", "together with", "in addition to", or "besides" is a parenthetical addition, usually set off by commas. It does NOT add to the grammatical number of the subject that precedes it -- the finite verb still agrees only with that head subject.

Application

The head subject of this sentence is "The minister" (singular). The phrase "along with his private secretaries" is exactly this kind of parenthetical addition: it is set off by commas and only supplies extra information, so it does not turn the subject into a plural "minister + secretaries". Since the head subject stays singular and the sense is present/near-future ("expected to arrive shortly"), the verb must take the singular present form "is", not the plural "are".

Cross-check

• is -- singular present-tense form of "to be"; it matches the singular head subject "the minister", so this is the required replacement.

• were -- plural (or subjunctive) past-tense form of "to be"; it would wrongly treat the subject as plural and shift the clause into the past, which the sentence does not call for.

• have been -- a present-perfect form of "to be", but the plural auxiliary "have"; a singular subject like "the minister" would need "has been", so this option is ruled out by number agreement, not by tense or aspect.

• No improvement -- would keep "are", the plural present-tense form of "to be", which does not agree with the singular head subject "the minister".

So the underlined "are" must be replaced with "is".