A lightweight material is being tested for effectiveness in blocking ultraviolet (UV) rays from the Sun that cause skin to burn and possibly develop skin cancer. Which method would be most helpful for testing this material?

The goal is to find out how effectively the material blocks UV rays, so the test should directly measure how much UV passes through it. Specialized equipment can measure the amount passing through different numbers of layers, letting researchers compare the material’s blocking ability. Surveying preferences does not measure UV protection, and testing damage to human skin is unnecessary and potentially harmful.

AI-written and checked against the verified answer.