Areport from the congressional budget office (cbo) noted, "real potential gdp is the maximum sustainable output of the economy adjusted to remove the effects of inflation." in early 2017, the cbo estimated that the gap between real gdp and potential gdp would fall from 1.1 percent in 2016 to 0.3 in 2018. in 2016, real gdp was $16.7 trillion, and the cbo's estimate of potential gdp was $16.9 trillion. the cbo forecast that potential gdp would increase to $17.4 trillion in 2018.cbo includes the word “sustainable” in its definition of potential gdp becausea. this is the level of gdp that can meet human development goals while maintaining the ability of natural systems to continue to provide the needed natural resources. b. this level of gdp is based on available renewable resources. c. given the available resources in the economy, this is level of gdp that can be maintained. d. this is the level of gdp at which the economy is free of poverty, hunger and environmental degradation.