HELP A STRUGGLING FRIEND OUT

An amusement park has opened a new roller coaster. It is so popular that people are waiting for up to 3 hours for a 2 minutes ride. Concerned about how people who might be willing to wait in line for 3 hours feel about this, they survey the first 100 people as they enter the park.
- What kind of sample is this?
A) a convenience sample ( I chose this answer and it wasn’t correct)

B) cluster sample

C) simple random sample

D) census