Definition: In this task, you are given inputs i, j, and A, where i and j are integers and A is a list. You need to find all elements of A from the ith element to the jth element, reverse the order in which they occur, and then concatenate them to output the resultant string. i and j will be non-negative, and will always have a value less than the length of A. i will always be less than j. Perform the operations in order, i.e., do not concatenate the elements and then reverse the string.
Input: 12, 12, ['M', '3915', 'C', '2023', '5465', '9635', 'w', '2971', 'H', '21', '1915', 'B', 'c', 'P', 'I', '4427', '645', 'x', 'v']

B