Correct Answer  Option 1 : 0
CONCEPT:

Perfectly elastic collision: A perfectly elastic collision is defined as one in which there is no loss of kinetic energy and momentum of the system is conserved in the collision.

Inelastic collision: A inelastic collision is defined as one in which there is a loss of kinetic energy and momentum of the system is conserved in the collision.

Coefficient of restitution is the ratio of relative velocity after impact to the relative velocity before impact.
Coefficient of restitution (e)
\({\rm{e}} = \frac{{{\rm{Relative\;velocity\;after\;collision}}}}{{{\rm{Relative\;velocity\;before\;collision}}}} = \frac{{{{\rm{v}}_2}  {{\rm{v}}_1}}}{{{{\rm{u}}_1}  {{\rm{u}}_2}}}\)
 For perfectly elastic collision, e = 1
 For inelastic collision, e < 1
 For a perfectly inelastic collision,e = 0
EXPLANATION:
As from the above discussion, we can say
 The coefficient of restitution for perfectly inelastic bodies is: e = 0
So option 1 is correct.