The equation y=1.07x+3.91 models the number of pieces of junk mail a person receives in a week, where x represents the number of credit cards he or she has. what does the y-intercept represent in the context of the situation? a. a person with 1 credit card can expect about 4 pieces of junk mail in a week b. a person with no credit cards can expect about 1 piece of junk mail in a week c. a person with no credit cards can expect about 4 pieces of junk mail in a week d. a person with 1 credit card can expect about 1 piece of junk mail in a week