Answer:
Internal validity.
Explanation:
Internal validity is the study in which trust relationship is build between treatment and outcome. This relationship is known as <em>cause-and-effect. </em>
In this type research, the studies are based on whether the finding is questionable or not. The research which can overrule the possibility of alternative explanations of our findings is internally valid.
The threats of internal valid study are:
- <u>Natural Improvement </u>
- <u>Maturation</u>
- <u>Historical Events</u>
- <u>Placebo effects</u>
- <u>Nonspecific effects</u>.
So, the correct answer is 'Internal validity'.
Jet stream and cold front of course
Your answer is b hope it’s right
Answer:immune
Explanation:
they produce anti bodies and are each programmed to make specific antibodies
