Which one of the following statements about a passport is correct?

Which one of the following statements about a passport is correct?
 
  a. A document given to a citizen by his or her own government granting permission to leave the country and to travel in only the specified foreign country at the time a passport is issued.
  b. A document given to a citizen by his or her own government granting permission to leave the country and to travel in a limited number of specified foreign countries.
  c. A document that verifies the identity and nationality of the bearer.
  d. A document that limits the time a traveler can stay in a foreign country.