computer architecture – What is the maximum memory address space that microprocessor can access directly if a 16-bit memory module is interfaced with a 32-bit microprocessor?

The Complete question is as follows :

Consider a single-address 32-bit microprocessor with 32-bit address bus and 32-bit data bus. Its
instructions composed of 1-byte opcode and 3-byte operand address.
What is the maximum memory address space that the microprocessor can access directly if a 16-bit memory module is interfaced with the microprocessor ?

I am confused as microprocessor is having 32-bit address bus and the memory module has 16-bit address lines. So, according to me total memory size of the memory module would be 2^16. But I don’t understand what will be the maximum memory space that can be accessed by microprocessor.

I have thought that if 16 address lines of microprocessor is connected to the 16 address lines of the memory module then we will have remaining 16 lines of microprocessor.

Any idea or knowledge regarding this would be helpful to let me think of its solution.