Which one is a run-on sentence?
a.
a camel can go without water for days and days, he stores water in the hump on his back.
b.
since the backroom was vacant, jim used it as a studio.
c.
because john assisted his neighbors, they were able to paint his house twice as fast.
d.
if that old, half-burned house were reconstructed, someone might buy it and move into it.