ou are provided with the following descriptions of data collected for dif- ferent research studies. For each description, identify the type of dataset it represents (e.g., cross-sectional, time series, panel data, or pooled cross-sectional). (a) Researchers collected annual GDP growth rates for the United States from 1990 to 2020. (b) A survey was conducted in 2021 where 500 individuals from various cities were asked about their monthly household income and expenditure. (c) Data was compiled on the annual sales and number of employees for 50 tech- nology companies over the last ten years