Select the sentence below that uses proper punctuation to separate a nonessential phrase from the main sentence.

The plants must be given the proper amount of sunlight and water explained the gardener in order for them to grow.
The plants must be given the proper amount of sunlight and water. explained the gardener in order for them to grow.
The plants must be given the proper amount of sunlight and water, explained the gardener, in order for them to grow.
The plants must be given the proper amount, of sunlight and water, explained the gardener in order for them to grow.