Name the following takeover defense tactics:

a. Issuing stock rights to existing shareholders, enabling them to purchase additional shares at a price below market value, but exercisable only in the event of a potential takeover.

b. The purchase of a controlling interest in the target firm by its managers and third-party investors, who usually incur substantial debt in the process and subsequently take the firm private.

c. Encouraging a third firm, more acceptable to the target company management, to acquire or merge with the target company.