Select the most appropriate option to substitute the bracketed segment in the given sentence. If there is no need to substitute it, select 'no substitution required’.
The unit twitched like a bird (preening it's plumage and becomes motionless).
1
preening its plumage and became motionless
2
No substitution required
3
preening it's plumage while becoming motionless
4
to preen it's plumage and becomes motionless