Correct!

The answer is "a"!

An untold countless number of angels were individually created!

While the Bible does not state the number of angels created, there are other references of quantity.

"He said, 'The Lord came from Sinai, And dawned on them from Seir; He shone forth from Mount Paran, And He came from the midst of ten thousand holy ones; At His right hand there was flashing lightning for them.'" (Deut 33:2)

"The chariots of God are myriads, thousands upon thousands; The Lord is among them as at Sinai, in holiness." (Ps 68:17)

"But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to myriads of angels," (Heb 12:22)

"Then I looked, and I heard the voice of many angels around the throne and the living creatures and the elders; and the number of them was myriads of myriads, and thousands of thousands," (Rev 5:11)

In an instance where a human being is indwelt with demons, the numerical term "legion" was mentioned. If taken literally, a Roman legion is comprised of 3,000-6,000 infantry and 100-200 calvary.

"For He had been saying to him, 'Come out of the man, you unclean spirit!' And He was asking him, 'What is your name?' And he said to Him, 'My name is Legion; for we are many.'" (Mark 5:8-9)