Actual sales values at split-off point for joint products Y and Z are not known. For purposes of allocating joint costs to products Z and Y, relative sales value at split-off method is used. An increase in costs beyond split-off occurs for product Z, while those of product Y remain constant. If selling prices of finished products Y and Z remain constant, percentage of joint costs allocated to product Y and product Z would
a. Decrease for product Y and increase for product Z
b. Increase for product Y and product Z
c. Decrease for product Y and product Z
d. Increase for product Y and decrease for product Z