Using the definite article would only be possible in your advertisement if the five categories had been previously mentioned or defined.
Once upon a time there was a princess who lived in a high tower. The princess had long golden hair.
Which princess? The one in the high tower. Now that we know which princess, we can use the definite article.
Since there is no plural indefinite article in English, we just use the bare word.
A team of researchers measured each of ten subjects' reaction time to a certain stimulus and calculated the mean, median, and standard deviation of the measurements.
This is the beginning of a description of a research project and the first time any subjects are mention. Thus they are indefinite until defined by this sentence. Which subjects? The ones whose reaction time was measured. I can now refer to them as the ten subjects.