The areas of two similar triangles ABC and PQR are 64 $$cm^{2}$$ and 144 $$cm^{2}$$ , respectively. If the greatest side of the smaller $$\triangle$$ ABC is 24 cm, then what is the greatest side of the bigger $$\triangle$$ PQR?

A

32 cm

B

24 cm

C

42 cm

D

36 cm