If you look at a square made up of alternating red and blue stripes for several minutes and then look immediately at a blank white sheet of paper, you will see a square with alternating green and yellow stripes. This effect results from pairs of that work .

aa

explanation:

literally the answer is aa. not kidding. aa is a group.

where is the

the secretary of state, appointed by the president with the advice and consent of the senate, is the president's chief foreign affairs adviser. the secretary carries out the president's foreign policies through the state department and the foreign service of the united states.

it would be d). more resources must be obtained to attain that combination of goods and services