For easier management of the host records of the company 4 zones should be used because
subdomain is part of a larger domain and the main domain which is the primary domain is the name which the company have decide to use which will represent the company website address and in a situation where the company
have different domain names in which they had registered, they will need to choose one among the domain which will inturn be their main domain.
Therefore for easier , efficient and effective management of the host records 4 zones will be the best zones to be used.
