How can I extract unique data from Excel to a table in R?

I have a dataset from an Excel sheet that contains District Names and Courses offered as columns. I am looking to extract districts WITHOUT courses a, b, c, OR, d.

I would like to have a table that would return something like the following:

district name	course A	course B	course C	course D
District 1	no	yes	yes	no.

Any guidance would be appreciated!