Introduction:
There are various types of rays that exist in the electromagnetic spectrum, each with different properties and characteristics. The speed of light is a fundamental constant in physics, and it is commonly known that light travels at a specific velocity. In this response, we will discuss the rays mentioned in the question and identify the ray that does not travel with the velocity of light.

Explanation:

A) X-rays:
X-rays are a form of electromagnetic radiation that has high energy and short wavelengths. They are produced by the interaction of high-speed electrons with matter. X-rays do travel with the velocity of light, as they are a part of the electromagnetic spectrum. Therefore, x-rays are not the correct answer.

B) Microwave:
Microwaves are a type of electromagnetic radiation with longer wavelengths than visible light. They are commonly used for cooking and communication purposes. Similar to x-rays, microwaves also travel with the velocity of light. Therefore, microwaves are not the correct answer.

C) Gamma rays:
Gamma rays are high-energy electromagnetic radiation that is produced during nuclear reactions and radioactive decay. They have the shortest wavelengths and highest frequencies in the electromagnetic spectrum. Gamma rays are a form of electromagnetic radiation and therefore travel with the velocity of light. Hence, gamma rays are not the correct answer.

D) Beta rays:
Beta rays are not actually rays but rather a stream of high-energy electrons or positrons emitted from a radioactive nucleus during beta decay. Unlike x-rays, microwaves, and gamma rays, beta rays are not a form of electromagnetic radiation. They consist of particles and do not travel with the velocity of light. Therefore, beta rays are the correct answer.

Conclusion:
Out of the given options, the ray that does not travel with the velocity of light is beta rays. Beta rays are not a form of electromagnetic radiation, unlike x-rays, microwaves, and gamma rays. They consist of particles and have different properties than rays that travel at the speed of light.

Option d is correct, beta rays does not travel with speed of light