A texas household receives a social security check for $1500, which it uses to purchase a $40 pair of shoes made in thailand by a thai firm, a $1240 television made by a korean firm in korea, and $220 on groceries from a local store. as a result, u.s. gdp
 a. increases by $1500.
 b. increases by $220.
 c. increases by $280.
 d. increases by $40