Choose the data technology $($Q$,$ H$,$ U$,$ or S$)$ that is most appropriate for each of the following business questions$/$scenarios and briefly explain your reasoning.

Q $$ Database Querying

H $$ Statistical Hypothesis Testing

U $$ Unsupervised Data Mining

S $$ Supervised Data Mining A$)$ I need to get data on all my on$-$line customers who were emailed a special offer last month, including their registration data, all their past purchases, and whether they purchased the product from the special offer in the $15$ days following receiving the email.