Final answer:
The nurse should administer Benztropine 2mg IM if the client with schizophrenia who began taking a conventional antipsychotic medication yesterday experiences blurred vision.
Step-by-step explanation:
The finding that indicates the nurse should administer Benztropine 2mg IM to a client with schizophrenia who began taking a conventional antipsychotic medication yesterday is Blurred vision. Benztropine is an anticholinergic medication that can help reduce the side effects of conventional antipsychotics, such as extrapyramidal symptoms. Blurred vision is a common side effect of conventional antipsychotics, and administering Benztropine can help alleviate this symptom.