Which answer corrects the shift in verb tense in the sentence?
before sarah left for camp, she says good-bye to her friends.
a. before sarah left for camp, she said good-bye to her friends.
b. before sarah is leaving for camp, she says good-bye to her friends.
c. before sarah will leave for camp, she says good-bye to her friends.
d. before sarah leaves for camp, she had said good-bye to her friends.