Final answer:
The coordinating conjunction 'or' in the sentence is connecting subjects, specifically between 'SpongeBob SquarePants' and 'my cousin.' The correct answer is option 1.
Step-by-step explanation:
In the provided sentence, the highlighted coordinating conjunction is "or". This particular coordinating conjunction is being used to connect subjects. In the sentence "SpongeBob SquarePants or my cousin left the garage door open", "or" serves to link the two potential subjects of the sentence — SpongeBob SquarePants and the speaker’s cousin. Essentially, this coordinating conjunction is offering a choice between two possible subjects who could have left the garage door open. Coordinating conjunctions, often remembered by the acronym FANBOYS (for, and, nor, but, or, yet, so), can join various elements of a sentence, such as objects, verbs, or complete thoughts, but they are not used to connect more than two independent clauses in a sentence. Furthermore, when coordinating conjunctions connect independent clauses, they usually require a comma. However, in the example given, no comma is needed since "or" is connecting just subjects, not independent clauses.