Since you did have an HDHP in December 2024, the correct answer there would be to select that you had Self only coverage in that month. Having that last month eligibility in December, 2024 allows you to make a full year contribution to your HSA for 2024 even if you only were covered for part of 2024. The kicker is that you need to maintain the HSA coverage for all of 2025 in order to be able to have made that full year contribution in 2024. Because you didn't have an HSA in 2025, the questions you are seeing are being used to establish that the HSA contribution you made in 2024 was fully eligible as a tax deduction for 2024. If it isn't, then there will be excess contributions to your HSA for 2024 based on not having the HDHP in 2025 and they will be subject to a 6% penalty tax on the excess contribution.
All that to say that absolutely do say that you had the HDHP in December 2024 for Self-only coverage. If you had the HDHP coverage for all of 2024, then you won't be subject to the 6% excess contribution penalty for not having the HDHP plan in 2025.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
