Yesterday night while having dinner, Harry, the eldest son of Mr. Smit

Indeed it has to with the possessive noun. I checked one of the grammar books (section possessive noun usage) and here is the extract:


The Possessive Case is now used chiefly with the names of living thing; as,
The Governor’s bodyguard; the lion’s mane.

So we must say:
The leg of the table [not, the table's leg].
The cover of the book [not, the book's cover].
The roof of the house [not, the house's roof).

- But the Possessive is used with the names of personified (When n inanimate thing has ascribed to it the attributes of a person it is said to be personified. objects; as, India's heroes; Nature's laws; Fortune's favourite; at duty's call; at death's door.

The Possessive is also used with nouns denoting time, space or weight; as, A day's march; a week's holiday; in a year's time; a stone's throw; a foot's length; a pound's weight.

-The following phrases are also in common use:-
At his fingers' ends; for mercy's sake; to his heart's content; at his wit's end; a boat's crew.

The possessive of a proper name or of a noun denoting a trade, profession, or relationship may be used to denote a building or place of business (church, house, school, college, shop, hospital, the atre; etc.) as,
She has gone to the baker's ( = baker's shop).
Tonight I am dining at my uncle's ( = uncle's house).
Can you tell me the way to St .Paul's ( ='St. Paul's church)?
I attend the Town High School but my cousin attends St. Xavier's.
He was educated ai St. Joseph's.

-When you are in doubt whether to use a noun in the possessive case or with the preposition of, remember that, as a general rule, the possessive case is used to denote possession or ownership. Thus it is better to say 'the defeat of the enemy' than 'the enemy's defeat', even though no doubt as to the meaning would arise.

- Sometimes, however, a noun in the possessive case has a different meaning from a noun
used with the preposition of; as,
‘The Prime Minister's reception in Delhi’ means a reception held by the
Prime Minister in Delhi.
‘The reception of the Prime Minister in Delhi’ means the manner in which the people
welcomed him when he entered Delhi.
The phrase 'the love of a father' may mean either 'a father's love of his
child' or 'a child's love of his father'.

so, the answer is C