The Country of Nemedia Does Not Trade with Any Other

The country of Nemedia does not trade with any other country. Its GDP is $20 billion. Its government collects $4 billion in taxes and pays out $3 billion to households in the form of transfer payments. Consumption equals $15 billion, and investment equals $2 billion. What is the value of the goods and services purchased by the government of Nemedia?

A) $3 billion
B) $5 billion
C) $17billion
D) There is not enough information to answer the question.