Correct option is D
Given - (Left) © 2 © # * 6 € 4 5 3 € 1 1 € 6 7 # 7 4 £ 6 € (Right)
such numbers are there each of which is immediately preceded by a number and also immediately followed by a number - pair (Number, Number, Number)
© 2 © # * 6 € 4 5 3 € 1 1 € 6 7 # 7 4 £ 6 €
only one pair have found.
Option d is correct.