Correct option is C
(b) BSF (Border Security Force) → A paramilitary force responsible for border security.
(c) NDA (National Defence Academy) → A training institute for the armed forces.
(d) ITBP (Indo-Tibetan Border Police) → A paramilitary force responsible for guarding the Indo-Tibetan border.
Odd One:
CRPF, BSF, and ITBP are all paramilitary forces.
NDA is a training academy, not a paramilitary force.
Therefore, NDA is the odd one out.