The answer is B.
The factor by which 2 changed to -10 is [tex]\frac{-10}{2},~or~-5.[/tex]
The change for the next term is [tex]\frac{50}{-10},~or~also~-5.[/tex]
Again, the change to the next term is [tex]\frac{-250}{50},~being~-5.[/tex]
Since the terms are consistently increasing by -5, that is your ratio. Your answer is B, -5.
