title: Dynamically edit multiple choice options in live Google Form using Apps Script
body: <p>I'm a high school teacher in L.A. trying to create a course registration system using Apps Script. I need the Google Form I'm using for this registration to: </p>
  
  <p>Question 1) Update the choices available in subsequent multiple choice questions on new pages based on a student's current response choices.</p>
  
  <p>Question 2) Eliminate choices from the form when a multiple choice option has reached it's "cap".</p>
  
  <p>Question 1 Example)
  A student registers for “tie-tying” in workshop 1, and gets taken to a new page. The Script edits the available choices on that new page based on the student’s first choice, and removes “tie-tying” from the list of possible choices on that new page, so “etiquette” is their only remaining option.</p>
  
  <p>Question 2 Example)
  Students can either register for “tie-tying” or “etiquette”, both responses are initially available in the Google Form. 30 students take the survey, all 30 register for the “tie-tying” workshop. The Apps Script references the response spreadsheet, realizes the “tie-tying” workshop is full, then removes it from the Google Form's list of possible choices. Student 31 goes to register, and their only option is “etiquette”.</p>
  
  <p>If my question has already been asked and answered (believe me, I did search!) I'd appreciate the redirection.</p>