Concept:Choosing the correct set of words that fit grammatically and contextually in the three blanks.
Explanation:Let us examine the meanings of the given words:
mandatory means required by law,
pay means to give money,
key means very important,
amazing means extremely surprising, and
all means the complete amount.
For the first blank, we need an adjective to describe the ID card, and
mandatory fits logically because ID cards are often compulsory.
For the second blank, after the preposition
to, we require a verb, so
pay correctly completes the phrase
used to pay taxes.
For the third blank, we need an adjective to qualify
documents, and
key meaning important or essential, makes perfect sense here.
Thus the correct sequence of words is
mandatory,
pay, and
key, which corresponds to the combination
ABC.
Answer:Option C.
ABC