Assume GDP is $19 billion. If consumer spending is $8 billion, financial investment is $2 billion, investment spending is $5 billion, business inventories are $3 billion, and government spending is $5 billion, then net exports must be equal to 
 A. $1 billion. 
 B. $2 billion. 
 C. -$2 billion. 
 D.$4 billion.
 E. -$4 billion.