Which of the following sentences contains a comma splice?
O Heather loves traveling with her best friends Robin and Brett, they have seen their favorite band at least 15 times together.
O Heather loves traveling with her best friends Robin and Brett; they have seen their favorite band at least 15 times together.
O Heather loves traveling with her best friends Robin and Brett: they have seen their favorite band at least 15 times together.
O Heather loves traveling with her best friends, Robin and Brett. They have seen their favorite band at least 15 times together.