Are they not marked with their proper names?

Conventional shotgun naming goes like this


less choke------------------------------------>more choke
cylinder-improved cylinder-modified-full-extra full

there are several chokes in between that I didn't mention like specialized skeet/trap chokes, chokes for steel shot etc.

You can just look at them and see which are less and more constrictive. In general, use cylinder and maybe modified for clays/doves. I'd lean toward cylinder or imp. cylinder. Nothing more constrictive than modified for steel shot on ducks unless it specifically says the choke is for steel shot.

or you could save everyone some time and just look in your manual. Or look at the Benelli website where I was able to pull up the Black Eagle in about 30 secs and see that it comes with C, IC, M, IM and F chokes.

Next time maybe try looking.

http://www.benelliusa.com/firearms/sbe2.tpl