Final answer:
A movable guideline involves taking a small slice of a previous subsection and moving it to the next position to become the new guideline. So, the correct answer is option b.
Step-by-step explanation:
The correct answer is Movable guideline.
A movable guideline involves taking a small slice of a previous subsection and moving it to the next position to become the new guideline. This is commonly used in various software applications and text editors to help users align and format their content. For example, in a word processing program, you can select a small portion of text, press the tab key to indent it, and create a new guideline for subsequent content.