When Measuring the Size, Depth, and Wound Tunneling of a Client's

When measuring the size, depth, and wound tunneling of a client's stage IV pressure ulcer, what action should the nurse perform first?

A) Perform hand hygiene.
B) Insert a swab into the wound at 90 degrees.
C) Measure the width of the wound with a disposable ruler.
D) Assess the condition of the visible wound bed.