Turbotax does a poor job for the description. you must check yes to the partnership ended in 2020. this checks the final K-1 box on the k-1 worksheet.
then you should be able to check complete disposition
be careful
you didn't say if this was owned through your brokerage a/c or outside of it like a privately held partnership. so what you need to enter and where can vary greatly.
i can assure you that if this is a publicly held partnership (part 1 box d) will be checked. the broker does not know your actual tax basis. That will come from a supplemental schedule that the partnership provides with the k-1. you use this to calculate your correct tax basis which goes on the 1099-B worksheet. the only info that gets reported on the k-1 partnership sales worksheet is any ordinary income from disposition, if it exists it will be a separate column on the sales schedule,
for a privately held partnership there too, you have to determine your tax basis. if applicable, the partnership should provide you with the amount of any ordinary income that needs to be reported under section 751
