DHCP provides a pool of addresses, Subnet Mask, DNS address, Default Gateway address.
The pool consists of 192.168.52.1 - 192.168.52.254 and the address 192.168.52.253 is excluded from the pool and is assigned to a router interface which is also assigned as the Default Gateway. However all of that is stated in the scenario, but the question is asking what is the next step for clients to receive addresses from the DHCP server that happens to be 172.16.32.15.
So what you need to do is assign the command ip helper-address to a routing interface that is closest to the clients so the DIscover messages can pass the routing interface and reach the server which is on another subnet. My guess is you do the command ip helper-address on the default gateway interface as that is the interface that routes out of that subnet.