A core competenceSelect one:Time left $1$:$18$:$52$Qut of A$.$ is an activity that a firm performs proficiently that is also central to its strategy and competitive success. B$.$ is typically results$-$based, residing in a company's tangible physical assets on the balance sheet. C$.$ is often grounded in a single department's set of knowledge and expertise. D$.$ detracts from a company's arsenal of competitive capabilities and competitive assets and is not a resource strength considered to be genuine. E$.$ is a proficiently performed external activity.