. (3pts) If GDP (measured in billions of current dollars) is $5,325, consumption is $3,698, investment is $721, government purchases are $1,008, and the imports are $100, then the net exports are: (a) $2. (b)-$2. (c) $102. (d) -$102. . (3pts) Consider the following production function, where z denotes productivity and n labor y = zn. What is the value of a that makes this production function constant returns to scale? (a) a = 1/2. (b) a = 1. (c) a = 0. (d) a = 1/3