Explanation

Option C is correct because authorized participants (APs) are indeed the only entities that can create or redeem new shares of an ETF directly with the fund sponsor. This is a key feature of the ETF structure that distinguishes it from mutual funds.

Option A is incorrect because the minimum size of creation baskets is determined by the ETF sponsor, not by the APs.

Option B is incorrect because the list of required in-kind securities for each ETF is published by the ETF sponsor or fund manager, not by the authorized participants.