At a station, Storm I of $5$ hour duration with intensity $2$ cm/h resulted in a runoff of $4$ cm and Storm II of $8$ hour duration resulted in a runoff of $8.4$ cm. Assume that the $\phi$ – index is the same for the both the storms. The intensity of storm II (in cm/h) is
- $2.00$
- $1.75$
- $1.50$
- $2.25$