He was driving to work. (long duration) He called me. (short duration)
A. When he called me, he was driving to work.
B. While he called me, he was driving to work.
C. While he was calling me, he was driving to work.

Random Topics:
Verb Patterns / IngModals and InversionCoordinate ConjunctionConjunctions - Conjunctive AdverbsCardiology ServicesTOEFLWho vs WhomCompliment, Congratulation, and HopeFuture Perfect TenseElectricity VocabularyOther quiz:
Simple Future Tense › ViewWill Richard get out of the hospital soon?
Yes, ________. __________in a few days.
A. he will. He’ll get out
B. He’ll. He’ll get out
C. he won’t. He’ll get out in a few days
D. he will. She will get out
Grammar › View
While Tom __________ a book, Marhta __________ TV.
A. was reading, watched
B. read, watched
C. was reading, was watching
D. read, was watching
Idioms › View“Out of order” means it ___.
a. is untidy
b. doesn’t work
c. is unavailable
Reported Speech › View
“I need to get a loan to buy a car.”
A. He said he needed to get a loan to buy a car.
B. He said he will need to get a loan to buy a car.
C. He said he would need to get a loan to buy a car.
D. He said he had needed to get a loan to buy a car.