Chefs use these machines to mix the ingredients. The given sentence is
Right Answer is: A
The given sentence is in active voice. It is simple form of present tense. The structures for active/passive voices are:
Active: Subject + verb (“s“ or “es” with singular noun) + object…
Passive: Object + Is/are/am + verb (IIIrd form) + by + subject…
So, based on the above structures, we can convert the given sentence into passive voice:
These machines are used by chefs to mix the ingredients.