Can someone explain me step by step whats happening and give the correct output as well?

Given the Python expression below, which of the following values will be assigned to x ? from functools import reduce x= reduce (lambda x,y:[y]+x, list (range (5) ), []) [4,3,2,1,0][0,1,2,3,4][5,4,3,2,1,0][5,4,3,2,1][1,2,3,4,5]