STOREY: BUILDING::

To figure out a similar pair, we first need to understand the pair already present.

A storey is a single unit or floor of the building; multiple storeys stacked on top of each other would make a building. So, the relationship is that of a part to a whole.

Similarly, a rung is the horizontal slab/ support that, when stacked on top of another, forms a ladder. So, rung: ladder is a similar pair.

Option A: A plot is the general sequence of events that make up a story, and an outline is the structured roadmap detailing the story's key moments. Plot or outline is not the unit of either, and hence is not a similar pair.

Option C: A cable is a mode of transportation connecting two ends of a mountainous region with a rope; an elevator is a mode of transportation moving up and down. 

Option D: Every skyscraper will have a foundation, but there will only be a single foundation. Foundations will not be in multiples stacked or arranged to form a skyscraper. Hence, it is not a similar pair.