The different steps in a nodule formation are given below-

(I) A matured nodule establishes a direct vascular connection with the host for exchange of nutrients

(II) Root hair curls and the bacteria invade the root hair

(III) Rhizobium bacteria contact a susceptile root hair, divide near it

(IV) The infection thread is produced earring the bacteria and grows into the cortex of the root

(V) The bacteria get modified into rod-shaped bacteroids and cause inner cortical layer and pericycle to divide to form nodule.

The correct sequence is -