Final answer:
Option (a), The term closest in meaning to "universe" is cosmos, and the term closest to "hypothesis" is suggestion. The scale factor a in physical theories is used to differentiate between static, expanding, and shrinking universes.
Step-by-step explanation:
The word that matches the meaning of "universe" from the provided options is cosmos. The universe refers to all of space and time, including all of the matter and energy within it. The term cosmos is often used synonymously to describe this vast entity, encompassing all of existence.
In relation to the second part of the query, the word that is nearest in meaning to "hypothesis" would be suggestion. A hypothesis is a proposed explanation for a phenomenon that can be tested through experimentation or investigation, much like a suggestion is a proposal or idea that is put forward for consideration.
When discussing physical theories of the universe, the concept of a scale factor a might be mentioned. This scale factor helps in distinguishing different types of universes, such as static, expanding, or shrinking universes, depending on their metric properties in cosmology and physics.