Answer:
An atom that loses a electron is called a cation and has an overall positive charge.
GPE = mgh (for objects close to earth where g can be considered to be constant) Where m is the mass, g is the acceleration due to gravity (which the question has told us to assume is 10ms^-2), and h is the height of the object.
Substituting the values in:
GPE = 70*10*10 = 7000J
The answer to your question is A. Have a great day