Context: The map below shows humidity in the lower atmosphere on October 28, 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 Asia 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. 13 grams of water vapor per kilogram of air
B. 9 grams of water vapor per kilogram of air
C. 19 grams of water vapor per kilogram of air
From the given choices, select the correct answer and reply with the letter of the chosen option.

C