Answer :
The subordinate clause in the sentence stated above is:
A. As I was walking
Comma is used as an indicator which serves as the boundary line between the independent and subordinate clauses. In this sentence, the independent clause is "I stumbled upon a beautiful seashell."
A. As I was walking
Comma is used as an indicator which serves as the boundary line between the independent and subordinate clauses. In this sentence, the independent clause is "I stumbled upon a beautiful seashell."
The subordinate clause in this sentence is A As I was walking
A subordinate clause begins with a conjunction or a relative pronoun and it doesn't have all the necessary information no convey an idea, Option A best represents this kind of clause, Options B and C are part of the main clause so they can not be considered as two different clauses.