In this task, you are given inputs 'i', 'j', and A, where 'i' and 'j' are integers and A is a list. A list is shown by two brackets and comma-separated numbers and characters inside, like ['1', '12', 'l']. You need to concatenate all elements of A from the ith element to the jth element, and then reverse the resulting 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 reverse first and then concatenate.

[EX Q]: 4, 4, ['675', 'e', 'A', 'H', 'O', 'E', 'g', 'j', 'j', '5167', '2367', 'u', 'E', '753', 'M']
[EX A]: H

[EX Q]: 9, 21, ['D', 'j', 'T', '91', 'W', '9709', 'H', '1023', '4595', '1241', '917', '383', '7739', 'G', 'I', 'b', '8401', '7941', 'j', '2713', 'K', '2443', 'E', 'B', '1515', '5141', '1221', '993']
[EX A]: K3172j14971048bIG937738371914215954

[EX Q]: 2, 3, ['C', '3929', 'B']
[EX A]:
B9293