Given the following NFA $N,$ where $=\{a,b\}.$ The language of $N$ is

The set of strings that alternate between $\text{'}$a$\text{'}$ and $\text{'}$b$\text{'}$

The set of strings that starts with zero or more $"$ab$"$ and end with a $\text{'}$a$\text{'}.$

none of these

The set of strings that start end end with $\text{'}$a$\text{'}$

The set of strings that contain the substring $"$ab$".$

The set of string that contain exactly two occurrences of $\text{'}$a$\text{'}.$

The set of strings that each of ones is a palindrome

give me the correct answer for above options