Many #teaching techniques (e.g., Mazur's Peer Instruction) suggest asking a (well-designed) #MultipleChoice question of the class and having them hold up #cards marked A/B/C/D.
... so you'd think someone would be manufacturing such cards. After *several minutes* of searching, pretty much all I can find are PDF templates to print out and cut apart with scissors.
Closest thing so far:
https://cardsfortheculture.com/products/fact-based-a-b-c-d-response-cards
There has to be a way to do this more cheaply. Also, having each letter a different color would make it easier to read the room.
After getting responses from several sources, I'm leaning toward just grabbing a box of colored cards like the one below and having the students write A/B/C/D on them with sharpies (which also dodges the colorblindness issue).
https://www.staples.com/Pacon-74170-2-x-3-Flash-Card-Dispenser-Box/product_485711
