Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the correct order to form a meaningful and coherent paragraph.

A. Quipu, a type of knotted rope employed by the Incas of South America, served as a memory aid.

B. Different colours were used to dye the strings.

C. Yellow represented money while red stood for battle or warriors.

D. Do you realise that five yellow knots represented five gold coins?