Which type of corporate action can only occur if a resolution is passed to forgo...

Pre-emption rights give existing shareholders the first right to buy new shares issued for cash, normally in proportion to their existing holdings, to protect them from dilution. A placing is an issue of new shares to selected investors, typically institutional investors, rather than offering them first to existing shareholders. Because this bypasses existing shareholders, a placing that issues shares for cash will usually require the company to disapply pre-emption rights, which is done through shareholder approval by resolution, subject to applicable company law and governance limits. A share buyback does not issue new shares, it repurchases existing shares and therefore does not require a waiver of pre-emption rights. A stock split changes the number of shares and the nominal value per share but does not involve issuing shares for cash to new investors. Warrant exercise results in new shares being issued, but it arises from contractual rights already attached to the warrants, and the pre-emption issue is addressed through the original terms and shareholder approvals at the time the warrants were created, rather than requiring a specific resolution to forgo pre-emption rights at the point of exercise.