Multi-choice problem: Continue writing the next sentence in this paragraph:

How to oxidize copper
Hard boil two or more eggs.
Two or three eggs should be plenty unless you have a large amount of copper to oxidize. Place them with their shells intact in a pot of water and bring to a boil for at least ten minutes.

Select from the following.
+ Do not place the eggs with their shells together, as they will melt and dissolve as they cook. Be sure to completely cover the surface and keep it moist.
+ Then drain the jars and transfer the eggs to a cooking pan so they'll continue to oxidize. Place two jars into a colander.
+ Don't worry about over-boiling them. In fact, that over-done greenish ring and sulfur smell is exactly what you need, since the sulfur will alter the appearance of your copper.
+ Boiling is most effective when the copper is fully dissolved, which typically takes between 20 and 30 minutes. You can still reintegrate the copper into the water once it's boiled.
Don't worry about over-boiling them. In fact, that over-done greenish ring and sulfur smell is exactly what you need, since the sulfur will alter the appearance of your copper.