During the newborn admission assessment, the nurse palpates the newborn's scrotum and does not feel the testicles. Which assessment technique should the nurse perform next to verify the absence of testes?

Use a fingertip to palpate the inguinal canal for a weakening or indentation

Measure the size of the scrotal sac for length and width.

Perform transillumination of the scrotal sac to visualize shadows of the testes

Observe the urethral opening on the surface of the penis when the newborn voids