Final answer:
The number of people at the event will be 4.
Step-by-step explanation:
To determine the number of people at the event, we need to consider that the number of people has doubled. Since there were initially 2 people, doubling that would give us 2 * 2 = 4 people. So, the answer is a) 4. In exponential form, we can represent the increase as 21 = 2, which means the original number of people 2 is multiplied by 2 once. In standard form, we can simply state that the number of people will be 4.