Which sentence correctly sequences the underlined verbs?

Ms. Garcia was leading a tour of the gallery when the fire alarm sounded.
Ms. Garcia had been leading a tour of the gallery when the fire alarm will sound.
Ms. Garcia was leading a tour of the gallery when the fire alarm sounds.
Ms. Garcia had been leading a tour of the gallery when the fire alarm sounds

Respuesta :

Ms. Garcia was leading a tour of the gallery when the fire alarm sounded.

This is correct because it is the only sentence where the verbs match tenses.