The term 'Pool-Heating Option' can be summarized by the solution 'SOLAR', which is a five letter word. SOLAR pool heating is an energy-efficient and cost-effective way to heat a swimming pool using the sun's energy. SOLAR pool heating systems use SOLAR collectors, which are typically mounted on the roof, to capture the sun's energy and transfer it to the pool water. This type of pool heating is becoming increasingly popular due to its environmental benefits and cost savings.