Which will be hardest to pull a block across a cork tile, sandpaper, polished table or a lab bench

And which would be easiest?

The easiest would be a polished table, but the hardest would be a tossup between the cork tile and the sandpaper.
It could be a very fine grit sandpaper, and a very soft cork tile.
You are probably expected to answer "sandpaper".

Here is the ranking of the surfaces, in increasing order of frictional force:

polished table
lab bench
sand paper (although it depends on the "grit", whether it's "fine" or "coarse")
cork tile

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