All of the following were innovations that benefited farmers during the second agricultural revolution except
a. the iron plough
b. the railroad
c. animal husbandry
d. plant domestication

Correct

d. plant domestication.

During the Second Agricultural Revolution the Dutch acquired the adjustable depth plow with curved molds with iron tip of the Chinese. The railroads reduced the cost of land transport by more than 95%. Animal husbandry was also used for meat, fiber, milk, eggs and other products.

the communist manifesto is an 1848 political pamphlet by the german near the end of the manifesto, the authors call for a "forcible overthrow of all existing social conditions",  ..

i think the answer is d. good luck.