Companies use global positioning system $($GPS$)$ tracking systems to track their salesforce because $\_\_\_\_\_\_\_.$

a$.$

it is impossible to reach out to customers without using such technology

b$.$

it is mandatory for logistics companies to know where their employees are at all times

c$.$

salespeople, in general, cannot be trusted with handling company profits

d$.$

salespeople prefer joining companies that use GPS

e$.$

it improves salesforce effectiveness and minimizes costs