Structural Spans

1) Can anyone clarify the spans for the following systems?

Concrete T beam

One Way Slab

Pan Joist

These are confusing me. And would they all be used for heavy loads?

2) What would be the best system for 20' span in commercial building?

A) Steel Decking and Concrete --> I believe these can go upto 15' but can span farther if deeper

B) Glulam --> 25'-65'

C) Wood Joist --> 25'

D) Wood I joist --> 45'

E) Waffle Slab --> 40'

Are my above spans correct? If so, I'd say the answer Is A.

A few factors would come into play to determine the best system e.g. intended loading, any dynamic loading (if so a stiffer system should be utilized), etc. it's hard to base a building material off a span as they can all span 20' efficiently for most part.