Two circles touch each other at point X. A common tangent touch them at two distinct points Y and Z. If another tangent passing through X cut YZ at A and XA = 16 cm, then what is the value (in cm) of YZ?

A. 1 : 2 B. 1 : 3 C. 1 : √3 D. 1 : √2

A. $$\frac{{23\sqrt {21} }}{4}$$ B. $$\frac{{15\sqrt {21} }}{4}$$ C. $$\frac{{17\sqrt {21} }}{5}$$ D. $$\frac{{23\sqrt {21} }}{5}$$

A. 80° B. 40° C. 90° D. 50°

A. 30° B. 40° C. 20° D. 70°