Please identify the primary key for the following relation.

Is it a single key or a primary key?

$\backslash$table$[[$ProductID$,$VendorID,AverageLeadTime,StandardPrice,LastReceiptCost$],[1,1,17,47\mathrm{.}8700,50\mathrm{.}2635],[2,104,19,39\mathrm{.}9200,41\mathrm{.}9160],[7,4,17,54\mathrm{.}3100,57\mathrm{.}0255],[609,7,17,25\mathrm{.}7700,27\mathrm{.}0585],[609,100,19,28\mathrm{.}1700,29\mathrm{.}5785]]$