Context: The map below shows air temperatures in the lower atmosphere on November 12, 2015. The outlined area shows an air mass that influenced weather in Europe on that day.
Look at the map. Then, answer the question below.
Data source: United States National Oceanic and Atmospheric Administration/Earth System Research Laboratory, Physical Sciences Division
Which air temperature was measured within the outlined area shown?
A. 5°C
B. -13°C
C. -20°C
From the given choices, pick the correct answer and respond by indicating the letter of the correct option.

B