You are cleaning a data frame with improperly formatted column names. In order to clean the data frame you want to use the clean$\_$names$()$ function. Which column names will be changed using the clean$\_$names$()$ with default parameters? Select all that apply.

$0\mathrm{.}25/1$ point

column $2$

column$\_3$

This should not be selected

Review

the video on cleaning data in R

$.$

column$\mathrm{.}1$

Correct

column$4$