All the regions of the electromagnetic spectrum travel at the same speed, which is the speed of light. The speed of light in a vacuum is approximately 299,792,458 meters per second. This means that no matter where in the electromagnetic spectrum a wave falls, it will travel at the same speed.

Explanation:
The electromagnetic spectrum is a range of frequencies of electromagnetic radiation, which includes radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. Each of these regions has a different wavelength and frequency, and they are all differentiated based on their properties and uses.

However, despite these differences, all electromagnetic waves travel at the same speed in a vacuum, which is the speed of light. This is because electromagnetic waves are propagated by the oscillation of electric and magnetic fields, and these fields travel at the speed of light.

This property of the electromagnetic spectrum is fundamental to many of its applications, such as in communication systems, where information is transmitted through radio waves, or in medical imaging, where X-rays are used to create images of the human body. The fact that all regions of the electromagnetic spectrum travel at the same speed means that these waves can be used interchangeably for different applications, depending on their properties and the desired outcome.

In conclusion, the answer to the question is option 'C', which states that all regions of the electromagnetic spectrum travel at the same speed. This is a fundamental property of the electromagnetic spectrum that underlies many of its applications and uses.