Final answer:
A label or heading that starts a section of a document is known as a heading. It provides information about the content of the section and aids in organizing the document.
Step-by-step explanation:
A label or heading that begins a section of a document is known as a heading. This term is used to describe a title at the top of a page or section that provides information about the content that follows.
For instance, in a document detailing various aspects of climate change solutions, "Adaptation" or "Mitigation" could serve as headings that indicate they are the start of new subsections. Headings are essential as they convey meaning, structure, and assist in organizing texts or multimedia compositions, enhancing both readability and accessibility.
The correct answer is d) Heading. A label or heading that begins a section of a document is called a heading. It helps to distinguish and organize different sections of a document. Headings are typically formatted in a larger and bold font to make them stand out.