Answer:
Print.
Step-by-step explanation:
A guide can be defined as a book that gives information about a topic or a subject. It is a document that provides information about a place or subject.
So, a guide to all the national parks located within the United States is a book that gives information about the locations of the national parks in the U. S. Thus the medium of this guide will be in print.
The guide will be provided in a print that will help the people to locate national parks in the U. S.
So, the correct answer is print.