If the curved surface area of a cylinder is 1760 cm2 and its base radius is 14 cm,

(c) 20 cm

Curved surface area $=1760 \mathrm{~cm}^{2}$

Suppose that h cm is the height of the cylinder.
Then we have:

$2 \pi r h=1760$

$\Rightarrow 2 \times \frac{22}{7} \times 14 \times h=1760$

$\Rightarrow h=\frac{1760 \times 7}{44 \times 14}=20 \mathrm{~cm}$