When the rf of one of the dots observed in a mixture after developing a tlc plate is coincident with that of the reference standard material (rsm), it means: ?

In thin layer chromatography, when the retention factor (RF) value of one dot observed in a mixture after developing a plate is coincident with the reference standard material, it means that one of the unknown compound is identical to the compound of a known structure or the reference standard material. Therefore, the unknown compound in a mixture was identified using thin layer chromatography.  

1. protection 2. homeostasis 3. storage4.blood formation5.bone marrow 6.movement

Ibelieve the answer is c.