Between 2015 and 2016, the CPI of a small nation rose from 180 to 185 . If household incomes rose by 5% during that period of time, which of the following is true? The purchasing power of household income rose between 2015 and 2016. The purchasing power of household income remained constant between 2015 and 2016. The purchasing power of household income fell between 2015 and 2016. The CPI cannot be used to determine how the purchasing power of household income changes over time