Answer:
A. Dichloromethane is the bottom layer
Step-by-step explanation:
The immiscibility of the mixture is note worthy. The question aims at knowing the relative position of aqueous substance and organic layers.
To know which layer is which it should noted that organic solvents like diethyl ether are most likely on top having a density less than water, except for halogenated solvents where the solvent density is greater than water example includes solve like dicholoromethane and family, which are typically on bottom.
In this case the aqueous solvent is on top and halide solvent at the bottom.