Answer: B. Bought the bonds from Dalrymple and sold them to the public
Explanation:
Investment Banks help companies issuing new securities in diverse ways to ensure that they raise the capital they are looking for. Some of the ways they help include; underwriting securities and market research. The main way they help companies issuing new securities however, is underwriting.
With Underwriting, the Investment Bank usually buys all the securities on offer from the Issuing company, then sells them at higher price to make a profit. This helps the issuing company because they get to sell all or most of their securities so it reduces uncertainty.
The Commonwealth Bank of Australia therefore bought the bonds from Dalrymple and sold them to the public.