Totem Transformation Question

[Running the Shadows]

I'm looking at the druid archetypes, and had a question about the totem transformation...

Each type I use the ability, do I pick a different option? Or am I bound into one permenantly? And if I do get to pick different options, can I only use one at a time? I'm using HL, and it seems that it railroads me into that end result. But is that true?

[Rathendar]

You can pick a different option each time you use it, but only 1 option per use.