In June $2017,$ Amazon announced that it was purchasing Whole Foods for $$13\mathrm{.}4$B$.$ While Amazon's market cap immediately rose by $$15\mathrm{.}6$B following the announcement, effectively making Whole Foods a 'free' purchase, the stocks for the rest of the grocery industry tumbled.CNBC REAL$-$TIMESUPERVALU$3\mathrm{.}34[-11\mathrm{.}17\%1$KROGER$20\mathrm{.}91[-14\mathrm{.}86\%1$TARGET$49\mathrm{.}95[\mathrm{.}9\mathrm{.}94\%1$DOLLAR GENERAL $66\mathrm{.}98|$ COSTCO$[-7\mathrm{.}38\%1168\mathrm{.}30[-6\mathrm{.}53\%1$a a & Wed Feb $14$ gRelaunch to updaFrom a five$-$forces perspective, why did grocery store industry stocks fall following the Amazon announcement? $($select all that apply$)$The bargaining power of substitutes went downThe bargaining power of suppliers decreasedThe bargaining power of buyers went up