Answer:
b) gradually transforms into other forms of energy.
Explanation:
Interstellar clouds are composed of gases, plasma and dust etc. So when the gravitation force becomes stronger the clouds starts to contract which results in the reduction of the gravitational potential energy. As the gravitational potential energy decreases, there is an increase in the kinetic energy in the form of heat and temperature. Thats why we say that upon contraction of the interstellar clouds the gravitational potential energy gradually transforms into other forms of energy.