Putting a Compass in a Magnetic Field

[joel amos]

Homework Statement

If you put a compass in a magnetic field, the compass will...
a) seek electrical charge concentrations.
b) line up in a direction perpendicular to the magnetic field lines.
c) swing randomly.
d) line up in a direction parallel to the magnetic field lines.

Which one is it? Why?

EDIT: I found it to be d.

 

[tiny-tim]

hi joel!

EDIT: I found it to be d.

ok, but why?

(what are compasses made of?)