**Stokes: A CGS Unit of Kinematic Viscosity**

**Explanation:**

Kinematic viscosity is a measure of the resistance of a fluid to flow under the influence of gravity. It is defined as the ratio of dynamic viscosity to density. The CGS (Centimeter-Gram-Second) system is one of the metric systems used to express physical quantities.

The unit of kinematic viscosity in the CGS system is the Stokes, denoted by "St". The Stokes is named after the British physicist Sir George Gabriel Stokes. It is defined as the viscosity in poise divided by the density in grams per cubic centimeter.

**Conversion Factors:**

To convert between different units of kinematic viscosity, we can use the following conversion factors:

1 Stokes (St) = 1 cm²/s
1 Poise (P) = 1 g/(cm·s)
1 m²/s = 10^4 St
1 m²/s = 10^3 P

**Comparison of Options:**

a) Stokes: This is the correct answer. The Stokes is a CGS unit of kinematic viscosity.

b) Pa-s: The Pascal-second (Pa-s) is the SI unit of dynamic viscosity, not kinematic viscosity.

c) m²/s: This is the SI unit of kinematic viscosity. It is not a CGS unit.

d) Poise: The Poise (P) is a CGS unit of dynamic viscosity, not kinematic viscosity.

In conclusion, the correct CGS unit of kinematic viscosity is the Stokes (option a). It is defined as the viscosity in poise divided by the density in grams per cubic centimeter.