Fill in the blank: When using A/B testing for email, it’s important to ____.
A) remember that A/B testing is only useful for larger organizations and isn’t useful until your company reaches a certain scale
B) test only one thing at a time so you can isolate the significant variable
C) never conduct an A/B test on more than 50 people, since your hypothesis might be wrong
D) test more than one thing to take advantage of the experiment