Among the following personnel, identify the employee who is working in the informal sector ?

A cycle-rickshaw puller

The correct answer is option (2) : A cycle-rickshaw puller

The informal sector typically includes workers who are self-employed or work for small enterprises, often without the benefits and protections of formal employment. Cycle-rickshaw pullers are often self-employed or work for small informal businesses.

Police constable, clerk in the electricity office, and nurse in a government hospital are generally considered to be working in the formal sector due to their employment under government or private organizations that provide regular wages, benefits, and legal protections.