Concept:X-rays were discovered accidentally during experiments with electrical discharge in gases at low pressure.Explanation:In 1895, German professor W.K. Roentgen was studying discharge through gases. He observed a new type of radiation from the discharge tube. This radiation could pass through materials that block ordinary light. He named them X-rays or Roentgen rays. X-rays are produced when fast-moving electrons hit a target of high atomic weight.Answer:B. W.K. Roentgen