To find out how many rubber balls Dylan should give to each game, we can divide the total number of rubber balls by the number of games:
\[ \text{Number of rubber balls per game} = \frac{1256}{13} \approx 96.61538461538461 \]
Since Dylan can't give a fraction of a rubber ball, we can round this to the nearest whole number. Rounding 96.615 gives us approximately 97.
Looking at the options given (60, 80, 100, 120), 100 is the closest reasonable choice to an equal distribution considering the rounding, while also being above the average calculated amount.
So, the best response is 100.