**Question:** X-rays were discovered in the year:

A. 1895
B. 1900
C. 1910
D. 1920

**Core Concept:**
X-rays are a form of electromagnetic radiation that have a high frequency and short wavelength. They were discovered by Wilhelm Conrad Roentgen in 1895, while he was experimenting with cathode rays in a vacuum tube.

**Why the Correct Answer is Right:**
X-rays were discovered by Roentgen in 1895, while he was studying cathode rays in a vacuum tube. The vacuum tube contained a target made of a fluorescent screen, which glowed when exposed to these high-energy rays. The discovery of X-rays revolutionized medical imaging and diagnostic procedures, leading to the development of radiography and its applications in clinical practice.

**Why Each Wrong Option is Incorrect:**
A. 1900 - This is incorrect because X-rays were discovered in 1895, not in 1900.
B. 1900 - Similar to option A, X-rays were discovered in 1895, not in 1900.
C. 1910 - This is incorrect as X-rays were discovered much earlier, in 1895.
D. 1920 - The correct answer is 1895, making this option incorrect as well.

**Clinical Pearl/High-Yield Fact:**
The discovery of X-rays in 1895 by Wilhelm Conrad Roentgen revolutionized medicine and paved the way for imaging techniques and diagnostic procedures. This led to the development of radiography, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), and other diagnostic tools, significantly improving the ability to visualize internal structures, diagnose diseases, and guide interventions. Understanding the history of medical imaging is essential for students studying radiology, nuclear medicine, and other related specialties. It is also relevant for physicians, as knowledge of diagnostic imaging techniques helps in explaining medical conditions to patients and making informed decisions regarding treatment options.