Algorithms | Analysis of Algorithms | Question 16

Consider the following three claims:

I [Tex](n + k)^m = \theta(n^m)[/Tex] where k and m are constants

II [Tex]2^{n+1} = O(2^n)   [/Tex] 

 III 2^{2n+1} = O(2^n)

Which of these claims is correct? (GATE CS 2003)