edited on 3/17: the Cars93 was preloaded in R, so I have no idea how should I provide it here.

can somebody please help write it in R and explain to me, I'm new to Rstudio

The `nlevels` command tells you the number of levels in a factor variable. Use this function in combination with `summarize_if()` to produce an integer vector showing the number of levels for each factor variables in the Cars93 data.

**(b)** `levels()` returns the possible levels of a factor variable. Use this function in combination with `select` and `map` to create a list of all the levels of the Manufacturer, AirBags, DriveTrain, and Man.trans.avail variables

**(c)** Use the `toupper()` command in combination with `mutate_if()` to produce a new version of Cars93 where every factor variable has been converted to upper case.