This question turns on one key phrase, the decision is based on an official policy, and that phrase is the test for sorting the options.
Because the decision is expressly policy-driven rather than an adjudication between competing claimants, the correct answer is this is an administrative function, as the Authority's decision is based on an official policy.
Another way to approach this is to ask what would change if the facts were different, and see which label survives under the facts actually given.
Testing the facts against each label shows that policy-based permit ceiling-setting is administrative in character. The correct answer is this is an administrative function, as the Authority's decision is based on an official policy.