शंकु के छिन्नक (frustum) का कुल पृष्ठीय क्षेत्रफल $(TSA)$ = $\ldots \ldots \ldots \ldots .$

• A
  $\pi l(r_{1}+r_{2})+\pi r_{1}^{2}+\pi r_{2}^{2}$
• B
  $l(r_{1}+r_{2})+r_{1}^{2}+r_{2}^{2}$
• C
  $\pi l(r_{1}+r_{2})+\pi r_{1}+\pi r_{2}$
• D
  $\pi(r_{1}+r_{2})+r_{1}^{2}+r_{2}^{2}$