From (such data) Wegener developed his floating continents theory. He envisioned an original super continent that crystallized(of) molten material (making up) the infant earth, eventually the mass (cracked) and broke into several pieces—the present continents.

A．For those of an aristocracy, the imagination is boundless, and for those of a democracy, the imagination is used to reach realistic goals.
B．For those of an aristocracy, the imagination is used to reach realistic goals, and for those of a democracy, the imagination is boundless.
C．For those of an aristocracy, the imagination is boundless, and for those of a democracy, the imagination is used to reach unrealistic goals.
D．For those of an aristocracy, the imagination is bound to be practical, and for those of a democracy, the imagination is used to reach realistic goals.

A．He doesn' t want his readers to be confused.
B．He wants to get to his point and not discuss definitions.
C．Many people have tried to define it, and he wanted to add another by giving his point of view.
D．He doesn' t think the other definitions are accurate.