Final answer:
The justification for allowing a tax credit for certain solar energy property is mainly promoting a government policy to use alternative energy sources for sustainability and economic benefits.
Step-by-step explanation:
Allowing a tax credit for certain solar energy property can be justified as promoting a government policy to use alternative energy sources. This is because governments often provide incentives to encourage the adoption of renewable energy technologies, such as solar power, in order to reduce reliance on non-renewable resources and promote environmental sustainability. The adoption of solar energy helps to diversify energy sources, increase energy security, and potentially lower energy costs in the long run. Tax credits for solar energy can also stimulate economic activity by creating jobs in the manufacturing and installation of solar panels.