Which one of these are correct?

Which of the following is correct regarding net exports? Net exports is always a positive number for countries such as Australia and China so contributes to GDP growth for these economies. Net exports is the value of exports of goods at constant prices less imports of goods at constant prices. -Net exports include the value of goods and services sold to overseas households, firms and governments less goods and services purchased by Australian residents, firms and government from overseas, Net exports include the value of goods and services sold to overseas households, firms and governments plus imports purchased by Australian residents, firms and government from overseas