A: X-rays can penetrate through the flesh but not through the bones.
R: The penetrating power of X-ray depends on voltage.

Options

A. Both assertion and reason are true and the reason is correct explanation of the assertion.
B. Both assertion and reason are true but reason is not correct explanation of the assertion.
C. Assertion is true but the reason is false.
D. Both assertion and reason are false

Answer

B

Explanation

Both assertion and reason are true but reason is not correct explanation of the assertion.
Hardness penetrating power of X-ray depends upon accelerating voltage applied across X-ray tube characteristic X-ray relate to the material of target X-ray can.t pass through matter of heaviour element like bones (which contain phosphorus and calcium) but can pass through matter of higher element as flesh (which contain oxygen, hydrogen and carbon)