Answer :
A prime number is a number that has only 1 and itself as factors.
If the number has any other factor, it is not a prime number.
So let's factor each number to find which one is prime:
[tex]\begin{gathered} 211: \\ 1,211\\ \\ \\ \\ 187: \\ 1,11,17,187\\ \\ \\ \\ 219: \\ 1,3,73,219\\ \\ \\ \\ 183: \\ 1,3,61,183\\ \\ \\ \\ 177: \\ 1,3,59,177 \end{gathered}[/tex]Therefore the only prime number is 211.
Correct option: a.