Arrange the following in the ascending order of wavelength (\( \lambda \)):
(A) Microwaves (\( \lambda_1 \))
(B) Ultraviolet rays (\( \lambda_2 \))
(C) Infrared rays (\( \lambda_3 \))
(D) X-rays (\( \lambda_4 \))
Choose the most appropriate answer from the options given below:
\[ \lambda_4 < \lambda_3 < \lambda_1 < \lambda_2. \]
Final Answer: \( \lambda_4 < \lambda_3 < \lambda_1 < \lambda_2 \).