The Basic Difference Between the Special and General Theories of Relativity

The basic difference between the special and general theories of relativity is that

A) the first deals with electricity and the second with magnetism.
B) the first deals with nonaccelerated observers and the second deals with accelerated observers.
C) the first assumes that the observers are at rest and the second allows the observers to move.
D) the first deals only with accelerated observers and the second deals with nonaccelerated observers.
E) actually there is no important difference between them.