What are the institutional mechanisms by which capital disappears from the public financial markets back into the pockets of investors?

In other words, how do firms give money back to shareholders $/$ investors?

IPO $($initial public offering$).$

SEO $($seasoned equity offerings$).$

Reverse mergers that are later sold to investors.

Delisting when the company merges or goes bankrupt.

Dividends and share repurchases.

Options a$,$ b$,$ and c only.