In the San Francisco Market,Kellogg's Raisin Bran Sells for $3

In the San Francisco market,Kellogg's Raisin Bran sells for $3.49 per box,and Post Raisin Bran sells for $3.39 per box.Both Kellogg's and Post promote their cereals with weekly coupons in the local newspaper.Kellogg's and Post are most likely engaged in ________.

A) vertical integration
B) exclusive distribution
C) dual distribution competition
D) intra-brand price competition
E) inter-brand price competition