Choose the statement that expresses the idea most correctly.

The word who/whom refers to the "people". In this context, "who" is the correct usage.

It is essential to understand the use of pronouns here. 'Who' and 'Whom' are relative pronouns. However, they are associated differently with personal and possessive pronouns. Whenever the subject is represented via personal pronouns (like he/she/it etc.), 'who' is utilized in the sentence. If the main subject can be replaced by a possessive pronoun (like him/her/his/their etc. ), we use 'whom' in the sentence. You can ask simple questions to understand this concept. For
example:

You can ask: "Who took my pencil?"
You say: "He/She took it" (personal pronouns)
You do not say: "Him/Her took it" (possessive pronouns)

You can ask: "Whom did you meet yesterday?"
You say: "I met him/her yesterday" (possessive pronouns)
You do not say: "I met he/she yesterday" (personal pronouns)

Hence, sentences wherein 'whom' is followed by/used alongside 'he' is incorrect. Luckily, all the options, except Option A, have this usage and can be easily discarded.