In a certain month, the reference crop evapotranspiration at a location is $6 \; \text{mm/day.}$ If the crop coefficient and soil coefficient are $1.2$ and $0.8,$ respectively, the actual evapotranspiration in $\text{mm/day}$ is

1. $5.76$
2. $7.20$
3. $6.80$
4. $8.00$