(A) hyperbole
(B) ** idiom
(C) allusion
(D) simile
EXPLANATIONS BELOW
Concept note-1: -idiom informal. B2. something that is very easy to do: The exam was a piece of cake.
Concept note-2: -: something easily done : cinch, breeze.
Concept note-3: -The phrase ‘Piece of Cake’ is used to describe something that is very easy to complete. Example of Use: “The boy found the project to be a piece of cake because it was incredibly easy.”
Concept note-4: -A piece of cake Meaning: To be easy. Example: No problem, it should be a piece of cake.