is called the "first" management function because all other management functions depend on it.

a. Leading

b. Organizing

c. Controlling

d. Planning

e. Motivating

Answer to question:

D.

Explanation:

Planning is a key factor during business. This is mostly discussed by "management", they do rely on it.

How do management rely on it?

Let's make this clear by giving an example:

All of a sudden, you suddenly lose lot's of money for a your business. You're not ready & worry about bankrupt.  

In this case above, if you have a PLAN, you can take it from there and stick to the plan rather than rushing.

Why does it matter?

Well, management make's the plan most of the time. Which is why they are responsible for it. Therefore, if management doesn't provide proper planning, the business could be in trouble.

Study:

How to plan:

Planning a long-term business:

answer; (a) calling people who have not shown interest in the product and asking them to buy it;