The maximum value of $Z=3x+4y $ subjected to the constraints $3x+7y ≤21, 5x+2y ≤10; x, y ≥ 0$ is :

$\frac{275}{29}$ $\frac{237}{19}$ $\frac{107}{29}$ $\frac{384}{29}$

$\frac{384}{29}$