Explanation:

- Option 1: Alotted

- "Alotted" is not the correct spelling; it should be "allotted." It refers to distributing a portion of resources, not suitable here without context.

- Option 2: Fixed

- "Fixed" means repaired or made firm. It's not commonly used in the context of creating a fund.

- Option 3: Set

- "Set" is the correct choice here. It means to establish or create, which fits well with the phrase "set up a special fund."

- Option 4: Built

- "Built" means to construct, generally referring to physical structures, not typically used for funds.