Choice A is the correct answer. Solve for the cooling constant $k$.

1. Given: $T(5) = 150$, so $150 = 70 + 110e^{-5k}$.
2. Isolate: $80 = 110e^{-5k}$.
3. Divide: $e^{-5k} = \frac{80}{110} = \frac{8}{11} \approx 0.727$.
4. Natural log: $-5k = \ln(0.727) \approx -0.318$.
5. Solve: $k = \frac{0.318}{5} \approx 0.064 \approx 0.063$.

💡 Strategic Tip: Use given data points to find unknown constants in exponential models.

Choice B is incorrect because this cooling rate is too fast. Choice C is incorrect because this is slightly too slow. Choice D is incorrect because this rate is way too fast.