7. Which of the following is the 1st law of thermodynamics?
(A) The entropy of the a system undergoing a spontaneous process must decrease.
(B) The heat of an open system must remain constant throughout the entirety of theprocess.
(C) A process’s change in Gibbs free energy can determine the process’s spontaneity.
(D) The change in a system’s internal energy is equal to the sum of heat added into thesystem and the work done by the system.