Scientific theories are usually A.
claims posed by individuals.
B.
unable to change as new data or technology emerges.
C.
supported by evidence and widely accepted by the community.
D.
based on opinions and feelings.

C

Explanation:

The scientist needs proof, to support the evidence.

answer would be b, a tariffs main purpose is to protect domestic production and jobs.

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 !