Which of the following is a strategy to make a company less attractive during a takeover?

The strategy that involves implementing Shark Repellent tactics is effective in making a company less attractive during a takeover because these tactics are designed specifically to deter hostile takeover attempts. Shark Repellent refers to various defensive measures that companies can adopt to make themselves less appealing to potential acquirers.

These measures might include adopting provisions in the company's bylaws to limit the ability of a hostile bidder to gain control, such as requiring a supermajority vote to approve any takeover or allowing existing management to issue new shares, which effectively can dilute the stake of a potential bidder. This approach creates barriers to entry that are aimed at protecting the company from unwanted acquisitions.

In contrast, increasing dividends for shareholders can make the company more appealing to investors seeking immediate returns and could potentially attract interest from acquirers. Issuing additional shares to dilute per-share value can be a defensive tactic as well, but it typically falls under Shark Repellent strategies; however, it's not as comprehensive in addressing various takeover approaches. Creating long-term promotional campaigns mainly focuses on enhancing the company’s market image and profitability, making it more attractive rather than deterring potential acquirers. Thus, implementing Shark Repellent tactics stands out as the most strategic means to protect the company from unwanted takeover attempts.