The battle between the Merrimack and the Monitor showed that?
a)new technology gave the Union an advantage.
b)surprise attacks were effective.
c)the South had better ships than the North.
d)the North and South were equally matched at sea.

d)the North and South were equally matched at sea

Explanation:

Battle of the Monitor and Merrimack, also called Battle of Hampton Roads, in the American Civil War,, notable as history's first duel between ironclad warships and the beginning of a new era of naval warfare.

The significance of the encounter between the USS Monitor and the CSS Merrimack (renamed the Virginia following the Confederacy's decision to secede) was the fact that it represented the first clash of ironclad naval vessels in history. Previously, warships were constructed of wood.

The two ships fought each other to a standstill but the Virginia retired, unable to inflict serious damage on the Monitor. Both sides claimed victory, but the continued presence of the Monitor neutralized the threat of the Virginia to the fleet.

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