The answer is D.
Factor production that could be changed during particular period is called Variable Factor of Productions.
Basically, factor of productions is divided to fixed and variable factor.
FIxed factors are the one that will always stay the same no matter how many products you made. For example electricity cost, building rent, etc
The variable factors differ depend on how product you produce, such as raw material.
Answer: working memory
Explanation:
The human brain contains both the automatic system, which controls around 80% of our actions and the executive system, which manages the remaining 20% and needs a deliberate regulatory effort.
The executive function includes verbal working memory and non-verbal working memory that determine how much effort and what kind of activities are needed to adjust the way the brain works automatically.

Alfonso's average speed was 400 meters per minute.
Answer: does it get their attention? does it work?
Explanation:
you want to ask those questions. If you are walking through a store and something catches your attention you automatically want to look at it.
it definitely has to work it order to sell it. that is my answer