Select all correct information about map reduce algorithm.

A) A data set is mapped into a collection of (key value) pairs in the mapping step

B) Mapping step produces intermediate results and associates' values with an output key

C) Shuffling step produces intermediate results and associates' values with an output key

D) Shuffling step groups intermediate results associated with the same output key

E) Reducing step groups intermediate results associated with the same output key

F) Reducing step processes groups of intermediate results with the same output key

G) Mapping step processes groups of intermediate results with the same output key