Hello everyone I have this question and I find it very difficult can anyone help me ?

I actually choose C because A we have WAS and B we have Were and these two we use them in the passive voice not active voice I am right? And this question want the Active Voice.

Which of the following sentences is in (active voice)?

a. Around 1000 B.C., iron (was) first smelted and used to create tools and utensils by many people of Asia and Europe.

b. Around 1000 B.C., tools and utensils (were) created by many people of Asia and Europe using smelted iron.

c. Around 1000 B.C., many people of Asia and Europe first smelted iron and used to create tools and utensils.

C is correct

the forms of "to be" can also be used as a linking verb, so it does not always indicate passive voice. But when paired with a past participle, as in A and B above, it does indeed indicate passive voice.

Thank you so much