Read the sentence and identify the antecedent that corresponds with the bolded pronoun.

Glassmaking was an honorable profession, but it could also be dangerous.

The pronoun "it" corresponds with the antecedent "glassmaking." If we replace the pronoun "it" with the suspected antecedent, we will be able to tell if we are correct: "Glassmaking was an honorable profession, but glassmaking could also be dangerous." Because this makes sense and retains the original sentence's meaning, we know that the pronoun "it" correctly corresponds to the antecedent "glassmaking."