The resultant of two forces $P \;N$ and $3\; N$ is a force of $7\; N$. If the direction of the $3\; N$ force were reversed, the resultant would be $\sqrt{19} N$. The value of $P$ is :

Question

( A ) 4 N
( B ) 3 N
( C ) 5 N
( D ) 6 N