The practical nurse (PN) observes that an unlicensed assistive personnel (UAP) is measuring the blood pressure of a client with an arteriovenous fistula in the left lower arm and a cast on the right arm. The UAP applies the blood pressure cuff on the client's thigh with the bladder over the anterior thigh directly above the knee. Which instruction should the PN provide?

The bladder of the blood pressure cuff should be positioned over the posterior aspect of the thigh.

The lower edge of the blood pressure cuff needs to be positioned six inches above the knee.

The blood pressure measurement will be more accurate if taken in the client's left upper arm.

Subtract 20 mm when recording the systolic measurement due to use of the larger sized cuff.