(a) Offer for sale
(b) Offer through a prospectus
(c) Private placement
(d) All of the above
Answer (b) Offer through a prospectus
Explanation: The primary market is the place where securities are made, while the secondary market is the place where those securities are exchanged by financial backers and investors. In the primary market, organisations offer new stocks and securities to the general society for the first time, for example, issuing shares with an initial public offering (IPO). Offering through a prospectus is a method used in the primary market to attract investors.