What is the correct expression for the gravitational potential energy of a body?

The gravitational potential energy of a body is given by the expression Ep = -GMm/r.
The gravitational potential energy of a body is zero when it is located at an infinite distance from the source of the gravitational field.
The gravitational potential energy of a body is always positive.
a) Only the first statement is correct.
b) Only the second statement is correct.
c) Both the first and second statements are correct.
d) All statements are correct.