To find the initial value of the temperature in degrees Celsius, we need to evaluate the equation \( 2x + 10 \) when \( x = 0 \) (which represents noon, the start time).
Substituting \( x = 0 \) into the equation:
\[ 2(0) + 10 = 0 + 10 = 10 \]
Thus, the initial value of the temperature at noon (when \( x = 0 \)) is \( 10°C \).
The correct response is:
10°C