Answer:
d. includes the sectors that conduct day-to-day transactions with the organization.
Explanation:
An external environment of an organization includes all the external factors, the competitors, suppliers, political environment, social environment etc:
The task environment is the one which is basically related to day to day task management, since exists in the external environment it includes, external factors like:
The suppliers, competitors, labor markets and the customers.
As these all are dealt in everyday transactions of the organization, it is part of task environment management.
