Step 1: Definition of Specific Conductance
Specific conductance ($\kappa$) is the conductance of 1 cc of solution.
Step 2: Effect of Dilution
Upon dilution, the total volume increases, which means the number of ions per cc (unit volume) decreases.
Step 3: Conclusion
Because there are fewer ions available to carry current in a given unit volume, the specific conductance decreases with dilution.
Final Answer: (c)