$4\mathrm{.}1$ What value does the weighted average cost of capital $($WACC$)$ serve to decision makers?

$4\mathrm{.}2$ At a board meeting a director remarks "selling preference shares with a return of $\backslash (9\backslash \%\backslash )$ or debentures with a return of $\backslash (9\backslash \%\backslash )$ is really one and the same thing".

The company has the option of raising the R$400000$ through either:

a$.$ The sale of $40000$ preference shares at R $10$ per share or

b$.4000$ debentures of R$100$ each.

NB: the tax rate is $\backslash (30\backslash \%\backslash )$

Do you agree with the director's assertion? Discuss with aid of calculations.