A new bark beetle has recently arrived at a forest near Peter's apartment. The beetle is known to infest and kill only about $12 \%$ of trees in a given area before moving on. Peter has noticed lots of dead and infested trees and wants to test the assumption about the number of trees that will be infected and killed. He decides to focus his efforts on examining if more than $12 \%$ of trees have been infested.

What should Peter state for the null hypothesis and alternative hypothesis?
a.) Null hypothesis: $p=0.12$
Alternative hypothesis: $p \neq 0.12$
b.) Null hypothesis: $p=0.12$
Alternative hypothesis: $p> 0.12$
c.) Null hypothesis: $p> 0.12$
Alternative hypothesis: $p< 0.12$

Step 1 ：The null hypothesis is a general statement or default position that there is no relationship between two measured phenomena, or no association among groups. In this case, the null hypothesis would be that the proportion of trees that the beetle infests is 12%, as it is generally known.

Step 2 ：The alternative hypothesis is what you might believe if the null hypothesis is concluded to be untrue. The alternative hypothesis is the opposite of the null hypothesis. Since Peter wants to test if more than 12% of trees have been infested, the alternative hypothesis would be that the proportion of trees that the beetle infests is more than 12%.

Step 3 ：Therefore, the correct answer is b.) Null hypothesis: $p=0.12$, Alternative hypothesis: $p>0.12$.

Step 4 ：Final Answer: \boxed{\text{b.) Null hypothesis: } p=0.12, \text{Alternative hypothesis: } p>0.12}.