$20.$ Taxes and the Cost of Capital. Here is Icknield's market$-$value balance sheet $($figures in $ millions$)$:Net working capitalLong$-$term assetsValue of firm$ $5502,150$$$2,700$DebtEquity$ $800\mathrm{.}1,900$$$2,700$The debt is yielding $7\%,$ and the cost of equity is $14\%.$ The tax rate is $21\%.$ Investors expect this level of debt to be permanent. $($LO$16-2)$a$.$ What is Icknield's WACC?b$.$ How would the market$-$value balance sheet change if Icknield retired all its debt?