What causes a disturbance that results in a wave?

Wave is the propagation of disturbance from place to place is a regular and organised way. The disturbance like friction between wind and surface water and Gravitational pull of attraction between Earth and moon also create waves.

Wave is the propagation of disturbance from place to place is a regular and organised way.

Examples:

Hence we can conclude that the disturbance like friction between wind and surface water and Gravitational pull of attraction between Earth and moon also create waves.

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layer a is the exosphere and layer b is the thermosphere.   is the answer i think but i hope this .

correct it is c.) b b