Electromagnetic waves with wave length are given.  Arrange these wavelengths in decreasing order of magnitude

a) ${\lambda }_1$are used to treat muscular strain                    b) ${\lambda }_2$are used by a FM radio station for broadcasting
c)  ${\lambda }_3$are used to detect fracture in bones             d)  ${\lambda }_4$are absorbed by the ozone layer of the atmosphere

• A

  ${\lambda }_1>{\lambda }_2>{\lambda }_3>{\lambda }_4$

• B

  ${\lambda }_2>{\lambda }_1>{\lambda }_4>{\lambda }_3$

• C

  ${\lambda }_1<{\lambda }_2<{\lambda }_3<{\lambda }_4$

• D

  ${\lambda }_1>{\lambda }_2<{\lambda }_3<{\lambda }_4$