Which of the following sets a represents a function

How many countries have portuguese as a national language?

The government of country a has determined there is a coal shortage a seed on mining reports as a result of these data the government decreases coal exports to other nations access to information country a

Religious conflict in northern ireland started with a) cultural differences resulting from viking invasions around 800 b) england’s split from the catholic church in the 1500s c) rebellions in ireland between 1916 and 1921 d) the norman invasion of england in 1066