Recall the chapter on research methods in your text. natural improvement, nonspecific treatment effects, and placebo effects are best seen as threats to the of outcome research.

Internal validity.

Explanation:

Internal validity is the study in which trust relationship is build between treatment and outcome. This relationship is known as cause-and-effect.

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:

So, the correct answer is 'Internal validity'.

the correct answer is "c": the pillars proclaimed his regret at the bloodshed at the battle of kalinga and his conversion to buddhism.

the kalinga war is considered as one of the largest battles in the history of india. it was fought between the between the maurya empire, which ruled the lands of what is now known as india at the time, and the independent feudal kingdom of kalinga.

the army of maurya empire, led by its king ashoka, fought a prolonged war against kalinga. the war ended around 262 bce with the victory of the maurya empire. it is believed that ashoka, after having witnessed the loss of many lives during this war, felt deep responsibility and eventually converted into buddhism.