Heating systems are used to help maintain a comfortable temperature. You can reduce the need for an active heating system by improving the design of the dwelling. This could include reducing window sizes, lowering the window U value, or increasing insulation. If the heating load in the thermal performance assessment is sufficiently low and it is realistic to not include a heating system, then the highest-scoring option is "no heating to be installed". However, if the heating load is high, and you need to include a heating system, you should try to select the most energy efficient option.
Apart from energy efficiency, other considerations include the upfront cost, maintenance costs, health and safety issues, reliability, and noise. For further details, refer to Energy Heating and Cooling.