Answer:
the correct one is the third :
can travel through a region void of matter and mechanical waves cannot
Step-by-step explanation:
Mechanical waves travel supported by a material medium, for example sound waves travel in air, the wave on a string travels on the string.
Electromagnetic waves are produced by the variation of electric and magnetic fields, after producing this variation by the lenz law the variation of one field induces the other, so these waves do not need a material medium to travel.
Of the final statements the correct one is the third :
can travel through a region void of matter and mechanical waves cannot