Context: The map below shows humidity in the lower atmosphere on October 17, 2013. The map shows specific humidity, a measurement of the amount of water vapor in the air. The outlined area shows an air mass that influenced weather in North America 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 specific humidity level was measured within the outlined area shown?
A. 11 grams of water vapor per kilogram of air
B. 12 grams of water vapor per kilogram of air
C. 4 grams of water vapor per kilogram of air
Identify the correct option from the choices provided and respond with the letter of the correct option.

C