From the words lettered A to D, choose the word that best completes each of the following sentences: It is too abstract..................concept for them to...

From the words lettered A to D, choose the word that best completes each of the following sentences:
It is too abstract..................concept for them to understand.

Answer Details

The correct answer is "a". Explanation: The sentence is referring to a "concept", which is a singular noun. The article "a" is used before a singular noun to indicate that we are referring to one instance of that noun. Therefore, "a" is the most appropriate article to use in this context, and it makes the sentence grammatically correct.