A:
Not all Home Theater systems have the option of sending audio from the TV using HDMI.
The optical cable option will work provided your receiver accepts an optical input. If not, the analog signal from the TV will send the audio just fine that way, also. However, for that, you may need a 3.5mm male to RCA cable, which is not included.
Sending the audio separately from the video will not affect the 3-D viewing.
Regular DVDs can be played in most Blu-Ray players, but you can connect a separate DVD player if you want to using the composite or component inputs.
Thanks for your interest in Samsung televisions.
--Mr.Samsung