The correct answer is: D. no article
We use no article before a general noun that refers to a class of things, not a specific thing. In this case, the speaker is not referring to a particular LCD television set, but to LCD television sets in general.
We use “a” or “an” before a singular common noun that refers to a specific thing. In this case, the speaker could be referring to a specific LCD television set that they have bought.
We use “the” before a singular common noun that refers to a specific thing that is already known to the listener. In this case, the speaker could be referring to a specific LCD television set that they have already mentioned.