When you order negative values you have to keep in mind that the larger the absolute value is, i.e. the number after the negative sign, the smaller the actual number is.
For example:
On Tamika's town, the temperature was -5.3ºC
On Mark's town, the temperature was -4.06ºC
"5.3" is larger than "4.06", which means that for the negative numbers:
A temperature lower than -5.3ºC will have an absolute value greater than "5.3"
Between the options, the only one that has an absolute value greater than 5.3 is D. -5.4ºC
-5.4ºC is less than -5.3ºC so this one could have been the temperature in Gina's town.