Why is work an extensive quantity?

(N/A) An extensive quantity is a physical quantity whose value is proportional to the size or amount of matter in the system. Work done in a thermodynamic process is given by the integral of pressure $P$ with respect to volume $V$,expressed as $W = \int P \, dV$. Since pressure $P$ is an intensive quantity (independent of the amount of matter) and volume $V$ is an extensive quantity (proportional to the amount of matter),their product (or the integral of their product) results in an extensive quantity. Therefore,work is an extensive quantity.