A Supply Curve Typically Slopes Upward Because _____

Multiple Choice

A supply curve typically slopes upward because _____

A) the opportunity cost of production increases as quantity supplied increases.
B) price and quantity supplied are inversely related.
C) quantity supplied is positively related to consumer income.
D) the substitution effect of a price change on quantity supplied is generally positive.
E) the income effect of a price change on quantity supplied is generally negative.