If a purple fabric is on rack two and red fabrics are on racks three and four, the green fabric must be on which of the following racks ? 

Ten fabrics of different colors are displayed on ten racks in a cloth store. The racks are placed one after another and numbered consecutively from one to ten. Each rack contains fabric of a single color. One fabric is green, two fabrics are brown, three fabrics are purple and remaining four fabrics are red. 

i) Purple fabrics are on racks one and ten. 

ii) Two brown fabrics are on racks next to each other. 

iii) No red fabric is on a rack next to a brown fabric. 

iv) No purple fabric is on a rack next to the green fabric.