Question

which of
these is not a medium
for
propogation of
sound?​

Answer 1

your question...:

Which of the following does not require a medium for propagation?A.water-waves B.radio-waves C.sound-waves D. Waves in string

your answer....:

Water waves, as the name suggests needs water as medium

Radio waves are electromagnetic waves and do not need a medium to propagate.

Sound waves needs a medium to propagate. The medium can be solid, liquid or gas.

Waves in string need the string to propagate.

Answer is B. radio waves.