Which speaker is expressing a viewpoint that is most consistent with the principles of laissez-faire economics?

I agree with the comment offered -- it would help if you'd give us the quotes or passages.  But let's at least define laissez-faire economics here.

"Laissez-faire" is French for "let do."  You can think of it as letting the economy do its own thing, without governments trying to interfere with it or control it.  This was an idea promoted by the Physiocrats in 18th century France.  They called themselves "Physiocrats" (those who believed in "rule by nature") because they thought trade and commerce should be allowed to proceed naturally.

The Scottish philosopher Adam Smith picked up on this idea also and promoted a capitalist economy in opposition to what he called a "mercantilist" economy where governments gave monopolies to certain merchants and tried to control business affairs.  

That president would be none other than president warren g harding , return to say of life before wwi