The correct answer is D) subheadings.
The element that helps to break up complicated steps a procedural document into more manageable chunks are subheadings.
When writing a procedural document, the use of headings and subheadings help the reader to better understand the list and if they are looking for a specific element or bullet, the reader can look for it more easily. Subheadings help us with a better structure in longe writings, four, five paragraphs or more, and it is a better way to expand content in the text.