The first investigators determined the uss maine sank because of a. a bomb onboard the ship. b. spies on the ship. c. a mechanical error. d. an outside mine.

The correct answer is D.  

USS Maine was an American ship that was sunk after an explosion, in the Havana Harbor in 1898, during the Cuban revolt against the Spanish colonizers. It became an outstanding issue in the US because it triggered its participation in the mentioned conflict.

The exact cause of the explosion remained unclear, although the most accepted version was the explosion of a mine outside the ship. Anyway, this event helped to encourage participation of the US in the war, as the idea of the Spanish as devils was rapidly spread among the US public opinion.

The correct answer is D

greenland

c tundra

iceland is grassland