question_answer

When ultrasonic, infrasonic and audible waves travel through a medium with speeds \[{{\upsilon }_{u}},{{\upsilon }_{i}}\] and \[{{\upsilon }_{a}}\] respectively, then

A)  \[{{\upsilon }_{u}},{{\upsilon }_{i}}\,and\,{{\upsilon }_{a}}\] are nearly equal  

B)  \[{{\upsilon }_{u}}\ge {{\upsilon }_{a}}\,\ge \,{{\upsilon }_{i}}\]

C)  \[{{\upsilon }_{c}}\le {{\upsilon }_{a}}\,\ge \,{{\upsilon }_{i}}\]

D)  \[{{\upsilon }_{a}}\le {{\upsilon }_{u}}\,and\,\,{{\upsilon }_{u}}\approx {{\upsilon }_{i}}\]