C-02-Q023mediumsingle_mcqWhich of the following is an infinite set?a{1,2,3}\{1, 2, 3\}{1,2,3}b{x:x∈N}\{x : x \in \mathbb{N}\}{x:x∈N}c{x:x\{x : x{x:x is a factor of 12}12\}12}d{∅}\{\varnothing\}{∅}