Please be so kind to answer the below question and show all calculations:

Question 1:

A company has financed 45% of its assets through a 11% after-tax cost of debt loan. The remainder of its assets are financed through equity. The firms required return on equity is 16%. What is the company's weighted average cost of capital (WACC)?

A. 11.25%

C. 28.50

B. 13.75%

D. 43.56%

Customer care Limited has determined its optimal capital structure, which comprises the following:
Form of capital	Weight	After-tax cost
Long-term debt	40%	6%
Preference shares	20%	10%
Ordinary shares	40%	9%
The weighted average cost of capital is ...
A. 5.3%.
B. 6.2%.
C. 8.0%.
D. 9.1%.

Thank you