Imagine you are working with a data file "gdp_eco80001.csv" that has two columns: date and gdp. (This question does not have a real data file attached). The goal of the code below is to: 1. load the "gdp_eco80001.csv" dataset 2. calculate the average GDP, and 3. create a line plot showing GDP over time. Choose the correct options in the dropdown boxes. library( [ Select ] openai tidyverse pwt10 data.table gapminder ) df <- [ Select ] data load_data read_data load_csv readRDS read_csv ("gdp_eco80001.csv") df %>% [ Select ] summarise filter stat arrange select calculate (average = mean(gdp)) df %>% ggplot(aes(x = date, y = gdp)) + [ Select ] graph geom_bar line_graph geom_point chart geom_line line ()  多重下拉选择题