Answer: A
Explanation:
Adjectival clauses also known as relative clauses are dependent clauses that describe a noun in sentences.
Punctuating adjectival clauses can be very problematic because you would have to say whether the adjectival clause in a sentence is essential or non-essential before using commas.
Essential Clause: This kind of adjectival clause is essential to the description of the noun. It is such that the sentence would be meaningless if it were taken out. E.g
The man whose house we just left loves you.
"whose house we just left" is an essential clause because there are many men in the world and without the clause we would not know the man that is being referred to.
Nonessential Clause: This is the opposite of essential clause. It is the kind of clause that a sentence can very much do without. E.g
His wife, who you have met, works at Microsoft.
"Who you have met" does not define the noun in the sentence and the sentence is still very much valid and understandable without the adjectival clause.
The rule is that, sentences with essential adjectival clauses are not punctuated while those with non-essential adjectival clauses are punctuated. As you can see in the examples above.
But with sentences that carry proper nouns e.g names of persons and places, commas are always used before their adjectival clauses because they are unique and do not necessarily need any more information.
That is why option A is the correctly punctuated sentence.
And option C is okay and doesn't need any punctuation.
