Resolution setting for 32 inch LCD TV as a PC monitor

I am using a 32 inch LCD TV as a PC monitor. And I have NVIDIA GeForce 8400 GS graphics card.

But unfortunately the highest resolution offered in my display settings is 1360x768.

I want to know whats the reason. I suspect the following 3:

1. Limitation of LCD TV


2. Limitation of Graphics Card


3. Limitation of Driver Software / some settings fine-tuning

I wish to have much higher resolution than 1360x768.