Concept:Distinguishing between “incidence,” “incident,” “accident,” and “accidence” based on meaning.
Explanation:“Incidence” refers to the rate or frequency at which something happens, especially crimes or diseases.
“Incident” means a particular event, often one that is unusual or unpleasant.
“Accident” means an unplanned, unexpected event that usually causes damage or injury.
“Accidence” refers to the part of grammar dealing with inflectional forms, such as verb tenses.
The sentence discusses the general frequency or occurrence of armed robbery, not a single event.
Therefore, the correct word is “incidence.”
Answer:C. incidence