Answer:
A) A battery, a coil of wire and a compass.
Step-by-step explanation:
When current flows through the coil it will produce magnetic field in the region of coil
This magnetic field is given by equation

here we know that
n = number of turns per unit length
I = current in the coil
So here we need
1). A coil of wire
2). A battery to produce current
Now this magnetic field is detected by a magnetic compass so next part we need is
3). Magnetic compass