Which of these numbers lies in the same residue class as 17 modulo 5?

Explanation

1. 01

   17 leaves remainder 2, so its class is $[2] = \{\dots, -8, -3, 2, 7, 12, 17, \dots\}$.

2. 02

   $-3 = 5 \times (-1) + 2$, so $-3$ is in it. 8, 21 and 14 leave 3, 1 and 4.