A specialty retailer of souvenir wear currently offers T-shirts, sweatshirts, and caps. Its most recent annual sales consisted of $18,000 of T-shirts, 59.000 of sweatshirts and $1.800 of caps The company is adding polo shirts to its product line next year and projects that this addition will result in new sales of $9.500. Existing sales will be affected by the Introduction of the new product as follows: $15,000 for T-shirts, $10,000 for sweatshirts, and $2000 for caps. What is the amount of only the side effects (erosion/synergy) of the additional product on existing sales? a) S420 b) -$750 c) $1,600 d) $7,700 e) -$1,800