What is the difference between a mechanical wave and an electromagnetic wave?

A: A mechanical wave travels through empty space, while an electromagnetic wave travels through matter.
B: A mechanical wave has a short wavelength, while all electromagnetic waves have long wavelengths.
C: A mechanical wave has a high frequency, while all electromagnetic waves have low frequencies.
D: A mechanical wave travels through matter, while an electromagnetic wave travels through empty space.

The right answer is : D - A mechanical wave travels through matter, while an electromagnetic wave travels through empty space.

Explanation:

Right on edg!

when a country suffers, for example, a drought period, the market product is affected for a low offer, in this case, potatoes; the government has to tax to the households, which have to give more money for the potatoes which they consume, that situation make them consume substitute goods even through loans, it could increase the financial market movement and the inflationary phenomena, the business has to increase salaries in order to the employees could buy a more expensive food (potatoes) and in order to inflation tha business had to buy expensive supplies in the factor market, while the rest of the world have to gain more money to consume the same amount of potatoes.