Karen created a sample of 20 students from a population of 100 in the following way. First, she gave each student a unique number from 1 to 100. She then obtained a list of 20 randomly generated numbers between 1 and 100. She used these numbers to identify which students to select. Here is the list of random numbers:

20 points! Please help! Which three students is part of her sample?
A. students 1, 10, and 20
B. students 12, 60, and 74
C. students 81, 89, and 90
D. students 3, 10, and 21