There are some adjectives that require only the definite article: wrong, perfect, right, etc. So, for example:
That's the wrong answer.
The Bentley is the perfect car for commuting.
He made the right choice.
So replacing all the the's with a's will be ungrammatical. However, in these examples the indefinite article would sound more logical, as the listener doesn't know what particular choice/car/answer the speaker's talking about. So, the question is: 1)What's the rule applied here? 2) Can you list other adjectives that require the definite article irrespectively?