The correct option is A h2h1
Pressure difference due to the same height of the same liquid will always be same.
Hence, in the two arms of the U−tube, pressure will be the same at surface D & B, as shown in figure.
pD=pB
Also, surface C and A are open to the atmosphere. Hence, both will have the same pressure (p0)
From, pD=pB
p0+ρ1gh1=p0+ρwgh2
Here, ρ1= density of paraffin
ρw= density of water
⇒ρ1ρw=h2h1
where ρ1ρw= relative density of paraffin