Under what circumstances are visas and passports especially important to consider?
a. when traveling within the united states
b. when vacationing with a friend
c. when selecting a new hobby
d. when traveling outside of your own country

D. WHEN TRAVELING OUTSIDE OF YOUR OWN COUNTRY.

A passport is issued by the country's government wherein an individual is a resident. It is a travel document that certifies the identity and nationality of the passport holder for the purpose of international travel.

A visa is issued by the government of the country the individual wishes to travel to. It can be a tourist visa, student visa, or worker visa.

One cannot travel outside his or her country without his or her passport. One cannot also enter any country without a corresponding visa.

Not what goes around on earth but the universe too.