Answer:
The top layer is most likely a Oil.
Step-by-step explanation:
When two immiscible liquids are mixed together they form two layers. These two layers are immiscible because of the polarity difference, one may be polar and the other one non polar. Among these two layers the layer with more density will form the bottom layer while, the one with less density will form the top layer. We are calling the upper layer as oil or lipids because these compounds have less density as compared to water. i.e.
Density of Water = 1 g.mL⁻¹
Density of Oils Ranges from 0.91 to 0.93 g.mL⁻¹