You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Question: 8 friends decides to eat pizza. 4 friends eat type 1 pizza which cost 100 each. Remaining friend buy pizza having off on it and saves 100 and each of them pay equal money .Total bill is 800. what is % of off on each pizza.

Option A: 20%

Option B: 30%

Option C: 10%

Option D: 15%

Option E: 25%
Option A