Final answer:
The gibbon is the most adept arboreal acrobat, the most frugivorous, and the most socially monogamous of all apes, known for their skillful tree-swinging and strong pair bonds.
Step-by-step explanation:
The ape that is the most adept arboreal acrobat, the most frugivorous, and the most monogamous (socially if not reproductively) is the gibbon. Gibbons, which belong to the family Hylobatidae, are smaller than the great apes and exhibit low sexual dimorphism with relatively longer arms for swinging through trees. They are highly skilled in arboreal locomotion and primarily consume fruit, making them frugivorous. Moreover, gibbons are known for forming strong social pair bonds, often regarded as monogamous relationships. This sets them apart from the other apes such as the more solitary orangutans, the sexually dimorphic and terrestrial gorillas, and the chimpanzees and bonobos which have complex mating behaviors and are not typically monogamous.