Final answer:
Both an increase in kinetic energy and a decrease in intermolecular forces are true when a transition between states is observed in the order of solid→liquid→gas.
Step-by-step explanation:
When a transition between states is observed in the order of solid→liquid→gas, both an increase in kinetic energy (Option A) and a decrease in intermolecular forces (Option B) are true. Converting a solid to a liquid and then to a gas requires an input of energy (heat) to overcome the intermolecular forces and increase the kinetic energy of the particles. Solids have strong intermolecular interactions, while gases have weak interactions. Therefore, transitioning from a solid to a gas involves an increase in kinetic energy and a decrease in intermolecular forces.