Final answer:
Larry Mullen and Adam Clayton are the drummer and bassist of the rock band U2, respectively. They are the only members to use their last names.
Step-by-step explanation:
Larry Mullen and Adam Clayton form the rhythm section of the iconic rock band U2.
As part of the band's lineup, they are known for their unique distinction: they are the only members who consistently use their last names.
Larry Mullen serves as the drummer, providing the essential percussive backbone of the band's sound, while Adam Clayton's role as the bassist lays down the harmonic foundation, anchoring the band's melodies and hooks.