Jack and Jill Decide to Start a Rumor That There

Multiple Choice

Jack and Jill decide to start a rumor that there will be no school on the following Monday. If each of them tells 1 person, and each of those people tells exactly 1 other person, and so on, how long will it take until all 1024 students in the school hear the rumor? Assume that everyone who knows the rumor will tell exactly one person every hour. That is, initially Jack and Jill know; after 1 hour, 2 more people know, . . . ​

A) 23 hours
B) 9 hours
C) 10 hours
D) 7 hours
E) 20 hours