Answer:
- rubber stoppers that seal the contents of flasks from the outside.
Explanation:
By looking at the meanings provided in the question, the first thing that can be implied for the word "septum" is that it is a kind of a separating wall or a hindrance or obstacle between two or more spaces. And the scientific meaning of "septa" refers to rubber stoppers.
So, taking the two words and their interpretations/ meanings into consideration, we can say that the word "septa" most likely means rubber stoppers that seal the contents of any flasks or container from the outside. And the very word "rubber stoppers" means that the objective of this item is to "stop" or "block" anything from 'escaping' or getting out of the flask or container.
Thus, the correct answer is the third option.