None of those are the usual 20" size. Those are some goofy size that only trials bike rides are made in, ISO 387 or something? Real 20" bicycle tires are ISO 406. They are common from 20 x 1.25" up to 20 x 2.4", with outliers in the 3.0" to 4.25" width range.
I don't know of any 20 x 2.5" tires for ISO 406, but I'm willing to be educated if there are any.