Step 1: Verify each location.
Barauni — Barauni Thermal Power Station (Begusarai, Bihar).
Kahalgaon — NTPC Kahalgaon Super Thermal Power Station (Bhagalpur, Bihar).
Kanti — Kanti Thermal Power Station (Muzaffarpur, Bihar).
Step 2: Synthesize.
All three are recognized thermal power plants in Bihar.
Step 3: Conclusion.
Therefore, the correct choice is (D) All of these.