What do all of these molecules have in common?
a. they store and transfer information.
b. they store energy.
c. they dissolve in water.
d. they are found in living things.

The answer is B) they store energy.
The answer isn't C because there are also molecules in water. The answer isn't D because molecules are not ONLY found in living things, in fact they are found in everything.

The correct answer is c

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.