Random Riddle: Oxy the Moron

Oxy the Moron set out into the world and learned a big word, OXYMORON!!! After searching about this new word for some time, he came up with a teaser made especially for you!

Can you figure out which well-known oxymorons these words are?
Ex) Initial facsimile = original copy

1) solitary option
2) approximately precise
3) trivial calamity
4) accurate approximation
5) authentic duplication
 

Random Riddle: Oxy the Moron