Allow students to request to see more answers

[kitsook]

• allow student to get more answers from the pool
• no upper limit? encourage students to see more answers?
• one button for each option. refresh all suggestions for that option. once hit certain limit (5), pull from seeded answers. once that exhausted too, dim the button. (downside: students will know the last suggestion(s) shown are seeded)
• re-phrase the description in Studio about the number of answers shown to students. That number is how many answers shown at once. It doesn't affect students requesting to see more answers