SPOT THE ERROR:I am going to the store tomorrow to get a cat and dog so I can walk them every day.

Explanation

"Dog" is incorrect. The sentence should use the indefinite article "a" before "dog" to maintain parallel structure with "cat." The correct phrase should be "to get a cat and a dog." There is an error here.The error in the sentence is the omission of the indefinite article "a" before "dog." The correct phrase should be "to get a cat and a dog" to maintain grammatical parallelism. Thus, the correct option to mark the error is C) Dog.