The correct answer is B.

In a public offering, an investment bank (or a group of banks) serves as an underwriter for the issuance of securities by a company or government entity. The underwriter purchases the entire issue from the issuer at a negotiated price and then resells the securities to the public, often making a profit on the spread between the purchase price and the public offering price. The underwriter assumes the risk of not being able to sell the entire issue to the public. In exchange for taking on this risk, the underwriter is compensated through the fees and the difference between the price paid to the issuer and the price at which the securities are sold to the public.

Choice A is incorrect. Private placement is a method of raising capital where securities are sold directly to a small group of institutional investors, not the general public. The underwriter does not purchase the entire issue and resell it in this approach.

Choice C is incorrect. In a best efforts approach, the underwriter agrees to sell as many shares as possible but does not guarantee the sale of all shares issued by the issuer. Therefore, this choice does not accurately describe a financing approach where the underwriter purchases and subsequently resells the entire issue.

Choice D is incorrect. A Dutch auction involves investors bidding on shares, with each subsequent bid being lower than the previous one until all shares are sold or no further bids are made. This method doesn't involve an underwriter purchasing and then reselling securities to public.