What Physical Mechanisms Most Probably Caused the Very Long Cracks

Multiple Choice

What physical mechanisms most probably caused the very long cracks and streaks that crisscross the surface of Europa,a moon of Jupiter?

A) They are the tops of gigantic greenhouses built by inhabitants of Europa to protect their cucumber crops.
B) They are frozen rivers that,in warmer times,flowed across the moon's surface.
C) Volcanic eruptions caused lava flows that then froze in place.
D) Tidal flexing and cracking of the surface,with subsurface fluids gushing upward and freezing