The Answers C
Probably not D, because its probably not that urgent as this machine can cause severe unconsciousness, or even death.
Maybe not A because it may not be there for the person for its too big, and it usually used in hospitals. Basically, its not portable.
Not B Either.
Awnser: <em>I</em><em> </em><em>would</em><em> </em><em>have</em><em> </em><em>to</em><em> </em><em>go</em><em> </em><em>with</em><em> </em><em>put</em><em> </em><em>on</em><em> </em><em>sunscreen</em><em> </em><em>3</em><em>0</em><em> </em><em>minutes</em><em> </em><em>before</em><em> </em><em>going</em><em> </em><em>into</em><em> </em><em>the</em><em> </em><em>sun</em><em> </em><em>and</em><em> </em><em>reapply</em><em> </em><em>regularly</em><em> </em><em>because</em><em> </em><em>yes</em><em> </em><em>while</em><em> </em><em>all</em><em> </em><em>the</em><em> </em><em>other</em><em> </em><em>options</em><em> </em><em>help</em><em>,</em><em> </em><em>sunscreen</em><em> </em><em>is</em><em> </em><em>usually</em><em> </em><em>your</em><em> </em><em>best</em><em> </em><em>bet</em><em> </em><em>when</em><em> </em><em>going</em><em> </em><em>into</em><em> </em><em>the</em><em> </em><em>sun</em><em>.</em>
Answer:
Environment
Explanation:
In a research study, internal validity refers to how well an experiment was carried out and to what extent the piece of evidence supports a claim.
The lesser the chance of confounding in a study the higher the internal validity.
Study of memory is possible through learning the electrical activity created by neurons.
Therefore, thunderstorm will affect the readings hence it is an Environmental threat to the internal validity.