The adjacent sides of a parallelogram are $$30\,\mathrm{cm}$$ and $$20\,\mathrm{cm}$$. The length of one diagonal is $$40\,\mathrm{cm}$$. What is the length of the other diagonal?

A

$$60\,\mathrm{cm}$$

B

$$10\sqrt{10}\,\mathrm{cm}$$

C

$$20\sqrt{5}\,\mathrm{cm}$$

D

$$8\sqrt{30}\,\mathrm{cm}$$