If you have three, you have three. If you have two, you have two but if you have one, you have none. What is it?

When you have three choices, you have three, you can choose anyone,

when you have two choices, you have two, you can choose either of the one

But, when you have one, then it just one and you have to go with it only. Because you have no choices

But, sometime picking the best choice out of available alternatives isn't that easy as it seems. More choices means that selection of one best choice going to be difficult

If there are three or two can choose from among the alternatives for the best alternative on the basis of the standard either in one state should study the alternative decision comes either rejected or approved

There are several wonderful answers herein already from great professionals, nothing to add

2 makes a couple and  3 makes a crowd,,,, but single is nothing...

Sometimes, objects works best with it supportive instrument, so in some cases it is considered  single object which should have its supporting object, if its not available, then its nothing,

e.g. A nut and screw....if nut is not there screw it self is nothing.Hope is makes sense.

Thanks

Fully agree with the answers given by Mr. Tariq Babaker and Mr. Sameer

i agree with Mr. Tariq , the answer is ( choices )

Thanks for the invitation, I agree with experts answer. ..

It is the opportunity. Or the moment of choice

I am just impatient to know the answer. Who will let the cat out of the bag?

you are left with no other option. 

than you for inviting i dont no the answer