In a study, both the researchers and the participants are unaware of the group assignments. a. controlb. double-blindc. pilotd. randomly assigned

B. double-blind

Explanation:

A double-blind study is one where neither the patients nor the experimenters knows who will be undergoing a specific treatment. The above method is used to eliminate bias in the outcomes of study.

These studies are especially helpful because of demand features or placebo effect to avoid bias.

For example, the researchers interacting with the participants would not know who was receiving the actual drug and who was receiving a placebo in a double-blind study.

every society, in order to meet the needs of it's people, has to answer three basic questions:

- what should we produce?

- how should we produce it?

- for whom should we produce it?

this questions must be answered in order to, option b, aid in production decisions.

every country can't produce everything, no matter how rich their land is. it may be a matter of technology, resources or geographical conditions. so, these three questions must be resolved in order to get the most of the production of each land.

hope this !