To find the initial value, we need to determine the temperature when \( x = 0 \).
Since \( x \) represents the number of hours after noon, at noon, \( x = 0 \).
Plugging \( x = 0 \) into the equation \( T = 2x + 10 \):
\[ T = 2(0) + 10 = 0 + 10 = 10 \]
Therefore, the initial value is \( 10°C \).
So the correct response is 10°C.