It would be nice to know your roster size when making this evaluation as I typically try to shy away from rostering 4 goalies in an H2H league. Losing those extra skater games can really hurt.
But since you already roster 4 goalies, I like the option of rolling with the two tandems. Mrazek and Reimer will likely split starts moving forward so it guarantees you all the games from two strong teams.
If you can get a good return on Markstrom, then option A is your best bet.