How should classification be done for a very small data set?
I don't think you need some classification algorithm, you can use your basic understanding on data/ Business Knowledge to do the classification. As the number of data points are too low, the model cannot give you good/generalised results.

Even if you try applying some complex algorithm like SVM/NN, it is of no use as the data is too low.

If you still want to apply some machine learning algorithm and then you can apply Naive Bayes, Decision Tree as these are the basic algorithms, can do the job.