The correct option is (d) All of the mentioned
For explanation: We can style the document using CSS in three different ways i.e embed, inline and external. In any way as mentioned, we can apply CSS. An inline CSS means applying styles rules directly to the element. In embed, we declare or write all the needed style in <style></style> tag in the head element of the document. Expect these two ways we can also use another way in which we can create an external style sheet and provide its link to the document.