Which of the following statements regarding the relationship between book value, sales price, and taxes are true when a firm sells a fixed asset?$1.$ Taxes are based on the difference between the book value and the sales price$\mathrm{.}2.$ Book value represents the purchase price minus the accumulated depreciation$\mathrm{.}3.$ There will be a tax saving if the book value exceeds the sales price$\mathrm{.}4.$ Taxes are based on the difference between the purchase price and sales price of the asset.