Young earth or Old earth?

Some suggest that there is a problem with young earth dating because of the evidence of mountains:

Genesis 7:17-22 states:Then the flood came upon the earth for forty days, and the water increased and lifted up the ark, so that it rose above the earth. The water prevailed and increased greatly upon the earth, and the ark floated on the surface of the water. The water prevailed more and more upon the earth, so that all the high mountains everywhere under the heavens were covered. The water prevailed fifteen cubits higher, and the mountains were covered. All flesh that moved on the earth perished, birds and cattle and beasts and every swarming thing that swarms upon the earth, and all mankind; of all that was on the dry land, all in whose nostrils was the breath of the spirit of life, died.

If the mountains were covered, then there were mountains before the flood, and mountains are the result of volcanic activity and geologic forces that require thousands, indeed, millions of years. However, this ignores one important matter, which is revealed in a simple question.

This opens the door to the reality that God’s creations reflect the appearance of age. If God does all of His Genesis creations in a matter of just days, then they will necessarily reflect age in its final form.

Question:  Is the Earth young or old, as in millions of years?

Answer:  Both.
Question: How old was Adam, in the very instant that God created him?

(A) Around 20 years old.
(B) One second old.
(C) All of the above.

Answer:  (C)