Question

how fast does radiation travel? a at the speed of light b too fast to measure c too slowly to measure d its impossible to tell since types of radiation travel at different speeds e at the speed of sound

Explanation:

Electromagnetic radiation (like light, X - rays, gamma rays) travels at the speed of light in a vacuum. Some particle radiation (e.g., alpha, beta) also approach this speed. Options B, C, D, E are incorrect as radiation speed is measurable, types like EM radiation have a consistent speed (light speed), and it's not sound speed.

Answer:

A. At the speed of light