What does the poles or zeros that gets coincide with each other can be regarded as?

What does the poles or zeros that gets coincide with each other can be regarded as?

a. Additive poles (or zeros )
b. Multiple poles
c. Simple Poles
d. Both (a & b)

Correct Answer : b. Multiple poles

Explanation :

Coinciding poles or zeros can be referred as 'Multiple Poles' whereas, non-coinciding poles or zeros can be regarded as 'Simple Poles'.