Recall the electromagnetic spectrum order

In the electromagnetic spectrum, wavelength increases in the following order: $\text{Gamma rays} < \text{X-rays} < \text{Ultraviolet} < \text{Visible} < \text{Infrared} < \text{Microwaves} < \text{Radio waves}$

Identify the given radiations

• A: Gamma rays $\,(\lambda_1)$
• B: X-rays $\,(\lambda_2)$
• C: Infrared waves $\,(\lambda_3)$
• D: Microwaves $\,(\lambda_4)$

Arrange in ascending order of wavelength

Since ascending order means from smallest wavelength to largest wavelength: $\lambda_1 < \lambda_2 < \lambda_3 < \lambda_4$

Match with the options

This corresponds to Option A.

Final answer

$\boxed{\lambda_1 < \lambda_2 < \lambda_3 < \lambda_4}$ So, the correct option is A.