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.