Discover the best answers at Westonci.ca, where experts share their insights and knowledge with you. Discover in-depth answers to your questions from a wide network of experts on our user-friendly Q&A platform. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

Two observers will always agree on:
a) The speed of light.
b) The lifetime of cosmic ray muons.
c) The lengths of objects.
d) The speed of sound.