Mark the consequence if it is intentional.
a.
europeans take corn to africa. corn becomes an important crop there.
b.
some sailors and conquistadors have smallpox. they come in contact with native americans who contract the disease and die after infecting their relatives and neighbors.
c.
affluent europeans buy sugar from merchants in european cities. millions of people in africa are kidnapped by african slave traders and sold to european sugarcane planters in the caribbean.