The wavelength ranges for the given electromagnetic waves are roughly:

1. AM Radio Waves: These have long wavelengths, typically in the range of hundreds of meters ($> 100 \text{ m}$). Thus, they correspond to $10^2 \text{ m}$. -> (a) matches (ii).
2. Microwaves: These range from millimeters to centimeters ($10^{-3} \text{ m}$ to $10^{-1} \text{ m}$). Thus, they correspond to $10^{-2} \text{ m}$. -> (b) matches (iii).
3. Infrared Radiation: These are shorter than microwaves but longer than visible light, typically $10^{-3} \text{ m}$ to $7 \times 10^{-7} \text{ m}$. Thus, they correspond to $10^{-4} \text{ m}$. -> (c) matches (iv).
4. X-rays: These have very short wavelengths, typically $10^{-8} \text{ m}$ to $10^{-11} \text{ m}$. Thus, they correspond to $10^{-10} \text{ m}$. -> (d) matches (i).

Correct matching: (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i).