To convert the measured volume from gallons to liters, we will use the given conversion factor where 1 gallon is equal to 3.78 liters.
The given measurement is 1.2 gallons.
Let's convert this measurement to liters:
[tex]\[ \text{Liters} = \text{Gallons} \times \text{Conversion Factor} \][/tex]
[tex]\[ \text{Liters} = 1.2 \, \text{gallons} \times 3.78 \, \text{liters/gallon} \][/tex]
After performing the multiplication, we get:
[tex]\[ \text{Liters} = 4.536 \, \text{liters} \][/tex]
Upon examining the provided options:
A. [tex]$0.8 \, \text{L}$[/tex]
B. [tex]$8.9 \, \text{L}$[/tex]
C. [tex]$4.5 \, \text{L}$[/tex]
D. [tex]$3.2 \, \text{L}$[/tex]
The closest and most appropriate answer to 4.536 liters is:
C. [tex]$4.5 \, \text{L}$[/tex]
So, the measurement of 1.2 gallons in SI units is approximately [tex]$4.5 \, \text{L}$[/tex].