Suppose the government decides to subsidize the cost of solar panels installed on taxpayer's homes by providing some sort of deduction or credit. Which form of tax subsidy provides the greatest possible benefit to an individual with a marginal tax rate of $30\%?$

Group of answer choices

Above the line deduction $($ie$,$ for AGI$)$ equal to $100\%$ of the costs incurred.

Below the line itemized deduction $($ie$,$ from AGI$)$ equal to $100\%$ of the costs incurred.

Non$-$refundable tax credit equal to $40\%$ of the cost incurred.

Refundable tax credit equal to $40\%$ of the cost incurred.