Which of the following is the first part of an internal and external style sheet that allows a developer
to locate any desired set of elements within a document?

A.
Frame

B.
IFrame

C.
Property

D.
Selector

Explanation:
A selector is used to select elements on an HTML page so that they can be styled. It can be applied to
all elements of a specific type, or only those elements that match a certain attribute. It is the first
part of the internal and external style sheet. It allows a developer to locate any desired set of
selected elements within a document.
Answer C is incorrect. A property is a style attribute that a user can change, and each property has a
value.
Answer A is incorrect. Frames are used to display more than one HTML document in the same
browser window.
Answer B is incorrect. An iframe is used to display a Web page within a Web page.