Matematika B - 2016. jesen, 9.

A. $3\pi \mathrm{c}\mathrm{m}3\; \backslash pi\; \backslash mathrm\{~cm\}$

B. $6\pi \mathrm{c}\mathrm{m}6\; \backslash pi\; \backslash mathrm\{~cm\}$

C. $9\pi \mathrm{c}\mathrm{m}9\; \backslash pi\; \backslash mathrm\{~cm\}$

D. $12\pi \mathrm{c}\mathrm{m}12\; \backslash pi\; \backslash mathrm\{~cm\}$