Fill in the blank with the correct option. One evening of each week w…

The correct answer is Option (1) → whosoever

Complete sentence: One evening of each week was set apart by him for the reception of whosoever chose to visit him. The evening was set apart for receiving any person who chose to visit him.

Option	Form and use	Example
(1) whosoever (answer)	Whosoever is an older, emphatic form of whoever, meaning any person who. It needs no noun before it and does two jobs at once: It is the subject of the verb "chose". Its whole clause ("whosoever chose to visit him") is the object of the preposition "of".	The prize will go to whosoever answers first.
(2) whichever	any one of a set of things or choices. It is not used for people in this way.	Take whichever pen you like.
(3) whom	Whom is the object form. It cannot be the subject of "chose". As a relative pronoun it needs a noun before it to refer to.	The man whom you met is my uncle.
(4) who	Who as a relative pronoun needs a noun before it ("those who chose"). On its own after "of" it does not make a complete phrase.	Those who chose to stay helped clean the hall.

Contrast: "who" needs a noun before it ("those who chose"). "Whosoever" needs none, because it means "any person who".