SSC CHSL 3-FEB-2017 SHIFT 3 TEIR 1 QUESTION 6 REASONING

6.Choose the odd word/letters/number/number pair from the given alternatives.
Options:
1. ABC
2. MNO
3. DEF
4. QRT
Answer: 4

ABC -> 1, 2, 3
MNO -> 13, 14, 15
DEF -> 4, 5, 6
QRT -> 17, 18, 20