What is a characteristic of the leader substitutes model?
a. it suggests that under certain conditions managers do not have to play a leadership role.
b. it states that rewards like stock options can substitute for someone in the leadership role.
c. it suggests that managers cannot substitute different leadership styles in different situations.
d. it advocates using coercive power to ensure high performance and the attainment of goals.

It says that managers don't have to play a leading role under certain conditions.

Explanation:

Leadership Substitute:

A characteristic of a delegate or a circumstance or condition in which leadership works in place of a leader, inappropriate in leadership. All Leaders of an organization can sometimes work very well without a director controlling the management.

The most important aspects of a company are effective leadership, many experts agree. But sometimes it's not necessary to have leadership.  

For example, Raj is a father and that he wants his daughter to do her work. Raj knows he can usually make his daughter do things if he gives her an exchange piece of candy.

However, it's the day after Halloween in this scenario but she already has chocolates. In this respect, Raj's power of leadership has been eliminated, since the normally used award is not effective.

this is all on your opinion. you choose what you want to do.