The correct option is A These ; aren't
A few words, though singular in nature, are made of paired items and generally treated as plural: scissors is one of them. Scissors is singular in form and plural in meaning, therefore, it requires a plural pronoun and verb in the given sentence. Scissors is one of those words that does not have a singular number. From the given options, we need to find words that are plural to agree with scissors. 'These and aren't' are plural whereas 'this and isn't' are singular. We need to fill in the blanks with plural words. Therefore, the correct option is: these; aren't. The other options have at least one singular verb or pronoun.