This "italicized" part of the sentence is an adjectival dependent clause. It acts as an adjective to the word motorist and cannot stand alone without putting it with an independent sentence, such as "The motorist lost his way."
The second one
is the best
Answer:
The purpose of the bobbin is to hold the thread that is held below the needle. The thread from the bobbin goes up through the plate and connects with the top thread to create a sturdy stitch when the machine is in use.
