Advanced British English Quiz; Lesson 3, Part 3

Level up your English from basic to intermediate and advanced.
British English Quiz, Lesson 3. Part 3.
Which group breaks the set’s unity?
legit, legitimate, genuine, authentic
bizarre, unconventional, eccentric, surreal
ratchet up, intensify, escalate, amplify
boil down, distil, stripping away, retrospective

Which group explains “tier”?
prune, trim, superfluous, conferred
level, rank, hierarchical stratum, layer
badge, emblem, insignia, token
mutations, predispose, unveil, disclose