Assertion :More is the cohesive force, more is the surface tension.
Reason :More cohesive force leads to more shrinking of liquid surface.

Surface tension can be understood as a property of a surface due to which it tries to acquire the minimum possible area. If cohesive force is more, the liquid is having the capability to shrink its surface more, i.e., surface area of the liquid is less and hence more is the surface tension.