Final answer:
The statement that indicates the effectiveness of preoperative lorazepam (Ativan) administration is "I can't remember anything about the surgery."
Step-by-step explanation:
Preoperative lorazepam (Ativan) administration aims to reduce anxiety and induce relaxation in patients before surgery. Thus, the statement that indicates the effectiveness of preoperative lorazepam (Ativan) administration is:
b. "I can't remember anything about the surgery."
Amnesia is one of the reversible effects of general anesthetics, and a client not being able to remember anything about the surgery suggests that the lorazepam has effectively induced amnesia.