Newbie question about wheels for indoor training

[monadnock]

Hi hubbers

New to the cycling world, so this might be the dumbest question of the day :-)

 

I have a 27.5 MTB, and picked up a second hand CycleOps Fluid2 for some indoor training.

 

I don't want to use the knobbly back wheel on the trainer, and my rear wheel's quick release doesn't fit the Fluid2 anyway.

 

What is my best option here?

 

Getting another 27.5 wheel with a smooth tire?

Buying a dirt cheap 2nd hand road bike for exclusive use on the trainer?

Sticking a road wheel on the mtb when training indoors? I can get a 10 speed road cassette (my mtb is 2x10), not sure if this will work?

 

What other options do I have?