Which quantitiy can be described as changing at a constant rate?
A
The number of people involved in a shared email, if each person must share the email they received with 7 new people.
B
The number of players left in a tournament, when half of the players are eliminated each turn.
C
A flu virus, which will infect 3 new people for every 1 person infected.
D
The total number of logs used for a bonfire, if 5 new logs are added each hour.