True are false?

Callable preferred stock is the stock of another firm that a corporation has a purchased as an investment.

True. Preferred shares normally carry a call provision, enabling the issuing corporation to repurchase the share at its (usually limited) discretion.

A preferred stock, also known as a preferred share or simply a preferred, is a type of stock. It typically gives the owner the right to collect a fixed dividend from the firm when funds are available for distribution, with higher priority than regular stock owners, hence the 'preferred' name. However, it generally does not give the owners any voting power in the decisions of the firm. In that sense it has a lower ranking than regular stock, and hence is more similar to debt. Also, the dividend owed to preferred shareholders is generally fixed and therefore they do not benefit from large dividend payouts, as regular stockholders do.

Therefore, you are correct. It is an investment made by the holding firm to have a guaranteed dividend or return for a certain amount of invested money.

Neither... or both.
Preferred stock is stock that (generally) pays a dividend. These preferred stockholders also have a preferred position (relative to shareholders of common stock) to be compensated if the company goes under.

The callable part means that the issuing company can 'call' or repurchase those preferred shares at their discretion.

Anyone, generally, can purchase preferred stock. So it could be purchased by a company, mutual fund or an individual.