Which two statements are true regarding indexes? (Choose two.)
A.
They can be created on tables and clusters.
B.
They can be created on tables and simple views.
C.
You can create only one index by using the same columns.
D.
You can create more than one index by using the same columns if you specify distinctly different
combinations of the columns.
On 12c is possible to create multiple indexes on the same column, so C would be correct.
confirmed.
A – https://docs.oracle.com/cloud/latest/db112/CNCPT/indexiot.htm#CNCPT721
D – “You can create multiple indexes using the same columns if you specify distinctly different permutations of the columns.” from above link.