[1] our house was once a stop on the underground railroad. [2] the underground railroad were a network of hiding places. [3] the cellar beneath our house has a secret door that was installed to trick slave catchers. [4] living in a piece of american history is pretty interesting.

which sentence has a subject-verb agreement error?
a) sentence 1
b) sentence 2
c) sentence 3
d) sentence 4

c. barbarians with unexpected intelligence  

most likely the answer would be a.) cupidity

definitions:

cupidity - greed for money or possessions

hydrophobia - extreme or irrational fear of water, especially as a symptom of rabies in humans

pathology - the science of the causes and effects of diseases, especially the branch of medicine that deals with the laboratory examination of samples of body tissue for diagnostic or forensic

patho -   relating to disease