(b)
Given equation of curve is $x = \alpha + 5\cos{\theta,}\ y = \beta + 4\sin\theta$
Or $\cos\theta = \frac{x - \alpha}{5},\sin\theta = \frac{y - \beta}{4}$
$\because\cos^{2}\theta + \sin^{2}\theta = 1$
$\Rightarrow \left( \frac{x - \alpha}{5} \right)^{2} + \left( \frac{y - \beta}{4} \right)^{2} = 1$
This represents the equation of an ellipse.