The thought of going onto the rollercoaster created a knot in my stomach.
A restrictive adjective clause is not set off with commas. The correct answer would be the first option. Restrictive clause is a clause that cannot be omitted in the sentence for it will change the idea of the whole sentence. It is the opposite of non-restrictive clause--a clause that serves as an additional information that is set off with commas.
Epistolary-which is the literary work in the form of letters.
