Change the following sentence into one expressing condition by the participle phrase.
In case you are not satisfied with the product, you can return it.

The correct option is D You can return the product provided you are not satisfied with it.
A phrase is a group of words that is an important component in any sentence. The participle phrase will begin with a present or past participle. The present participle phrase ends with -ing. The past participle phrase ends with -ed, -d, -t, -en, or -n.

Thus, option C is the correct answer as 'provided' is used as a past participle.