I'd go with d.

"them" is faulty --- its supposed to refer to the museum. Doesnt work.

down to A, C, D

C - and it request to - just doesnt seem to fit with the sentence

A - request <------> should --- don't go together. I request you to consider my plea. I request that you should consider my please. "Should" is more like a command which doesn't go well with 'request'

Left with D. But "who" here seems to be referring to "authorities"... who is supposed to be used for human beings according to the MGMAT book.. But D is the best of the lot.

This is a classic example of subjunctive use. Words like 'Demand, dictate, insist, propose, mandate, request, recommend, require' etc which signify wish, request, demand, command i.e. something contrary to what is true require subjunctive verbs which follow definite rule.

Subjunctive form never uses 'should'. so answer should follow this syntax

Marker word - that - Noun - Plural verb (Subjunctive always take plural verb irrespective of subject (singular/plural)

answer should read -

who request that it i.e. Option D.

thanks