Suppose you submit the DATA step below in a SAS windowing environment. If the active window displays the message DATA step running for a long time, what probably happened?

data work.groups;

set sashelp.class;

if age $<13$ then group $=$ 'Pre$-$teen';

else group $=$ 'Teen';

You misspelled a keyword.

You forgot to end the DATA step with a RUN statement,

You specified an invalid data set option.

Some data values were not appropriate for the SAS statements that you specified.