Final answer:
The word 'perturbation' in the sentence is best matched with 'disturbance' as it signifies a disruption of peace or order that would prompt someone to call the police.
Step-by-step explanation:
The word perturbation in the sentence "The elderly lady called the police to report the perturbation," is best matched with the word disturbance. Perturbation refers to an agitation or a disturbance of peace, quiet, or order.
Therefore, when the elderly lady called the police, she was likely reporting some kind of commotion or disorderly conduct that was troubling to her.