Answer:
c. it is ok to omit quotation marks for a paraphrase of the source.
Explanation:
Plagiarism can be defined as the act of representing or using an author's work, ideas, thoughts, language, or expressions without their consent, acknowledgement or authorization.
In order to avoid plagiarism, it is very important and necessary to reference or cite the source of the informations and data.
However, when citing an Internet source, it is ok to omit quotation marks for a paraphrase of the source because the idea, thoughts or intellectual work as being rephrased.