To convert from degrees Celsius to degrees Fahrenheit, you can use the formula:
\[ F = (C \times \frac{9}{5}) + 32 \]
Substituting -45 degrees Celsius into the formula:
\[ F = (-45 \times \frac{9}{5}) + 32 \] \[ F = (-81) + 32 \] \[ F = -49 \]
Therefore, -45 degrees Celsius is equivalent to -49 degrees Fahrenheit.
The correct response is: -49 degrees Fahrenheit.