Final answer:
The text feature that previews the content of an upcoming paragraph is the subheading, which acts as a guide to the structure and topics within a piece of writing.
Step-by-step explanation:
The text feature that previews the paragraph that follows is the subheading. A subheading is used to group related information and clearly describe sections of text which are forthcoming. Subheadings serve as organizational aids, offering readers a glimpse into the content of the next section and can be thought of as signposts that guide readers through the structure of a piece of writing.
A subheading is a title or heading that appears within a larger section of text. It is used to organize and provide a preview of the content that follows. Subheadings often give readers a sense of what they can expect to learn or find in the paragraph that follows.