The opportunity cost of any action is a. All the possible alternatives not chosen
b. The next best alternative not chosen.
c. The time required but not the monetary cost
d The monetary cost but not the time required.​

answer: what was the us involvement in ww1? although the u.s. tried to remain neutral when ww1 broke out, it finally joined on april 6, 1917 after declaring war on germany. the reason for america to become involved in ww1 was germany's unrestricted submarine warfare, which had already sunk several american merchant ships.

explanation:

i really really really really really really dont know

the border between arizona and new mexico is a thin, black line; this indicates a state boundary.

its correct: it's a thin line, and it's a state boundary, correct