which audio output do I use to run audio to my hdtv?

Lester Bandy, this will depend on what audio input you have on your TV. Check the image and see which connector should work for your TV

4 center/subwoofer connector

Use the orange connector to attach a speaker to a Low Frequency Effects (LFE) audio channel. LFE audio channel is found in digital surround sound audio schemes that

carries only low frequency information of 80 Hz and below. The LFE channel drives a subwoofer to provide extremely low bass extension. Systems not using subwoofers can shunt the LFE information to the main speakers in the surround sound set-up.

5 line-in connector Use the blue line-in connector to attach a record/playback

device such as a cassette player, CD player, or VCR. On computers with a sound card, use the connector on the card.

6 front L/R line-out connector

Use the green line-out connector (available on computers with integrated sound) to attach headphones and most speakers with integrated amplifiers. On computers with a sound card, use the connector on the card.

7 microphone Use the pink connector to attach a personal computer microphone for voice or musical input into a sound or telephony program. On computers with a sound card, the microphone connector is on the card.

8 side L/R surround connector

Use the gray connector to provide enhanced surround audio for computers with 7.1 speakers. On computers with a sound card, the microphone connector is on the card.

9 rear L/R surround connector

Use the black surround connector to attach multichannel capable speakers.