Final answer:
The null hypothesis can be rejected at a significance level of 0.05 and 0.01, but not at 0.1.
Step-by-step explanation:
When conducting a hypothesis test to check if the average population height is more than 170 cm, we calculate the p-value. The p-value represents the probability of obtaining a sample mean as extreme as or more extreme than the observed sample mean, assuming the null hypothesis is true. The p-value is compared to the significance level (alpha) to decide if the null hypothesis should be rejected or not. Given the choices, we can reject the null hypothesis at a significance level of 0.05 (option 2) and 0.01 (option 1), but not at a significance level of 0.01 (option 4) or 0.1 (option 3).