Using a loyalty card at the local gas station store, ella gets a free soda after buying 5 sodas at the regular price of 89¢. same-sized sodas at the local fast food restaurant are 79¢ each. how do the two deals compare if ella buys 6 sodas?

a ella saves 50¢ by purchasing her sodas at the fast food restaurant

b ella saves 60¢ by purchasing her sodas at the fast food restaurant

c ella saves 29¢ by purchasing her sodas at the gas station using the loyalty card

d ella saves 31¢ by purchasing her sodas at the gas station using the loyalty card