(A): Sky wave signal are used for long distance radio communication. These signals are in general, less stable than ground wave signals.
(R): The state of ionosphere varies from hour to hour, day to day and season to season.

Options

A. Assertion and reason are true and reason is the correct explanation of assertion
B. Assertion and reason are true but reason is not correct explanation of assertion
C. Assertion is true but reason is false
D. Assertion is false but Reason is true.

Answer

A