What is protect in a passive voice?
The passive voice must have the verb 'to be' in the correct
tense plus the past participle of the main verb. Here are some
examples:
I do (active)/it is done (passive)
I did (active)/it was done (passive)
I am doing (active)/it is being done (passive)
I was doing (active)/it was being done (passive)
and so on
So to change protect into the passive would be I protect
(active)/ It is protected (passive)