Hobson's choice
A Hobson's choice is a free choice in which only one thing is actually offered. The term is often used to describe an illusion that choices are available. The best known example is "I'll give you a choice: Take it or leave it", wherein "leaving it" is strongly undesirable.
The phrase is said to have originated with Thomas Hobson (1544-1631), a livery stable owner in Cambridge, England, who offered customers the choice of either taking the horse in the stall nearest to the door or taking none at all.