The inca empire was conquered by a. cabral b. cortes c. de gama d. pizarro

The Inca empire was conquered by Pizarro.

Explanation:

Francisco Pizarro was Spanish in his origin and started working as a swineherder in young age. Later in his life, he became a soldier, and went to Hispaniola with the new Spanish Governor of the New World Colony in 1502.

During his service under Spanish conquistador Ojeda he went on an expedition to Colombia in 1510. He was also with Balboa during the discovery of the Pacific Ocean in 1513. During his expeditions, he got to know about the enormous wealth of an Indian civilization based in South of America. In 1524, to explore this wealth, he reached the South America’s western coast with conquistador Almagro. There he came across the Inca Empire, which was one of the largest of the four grand civilizations and was spread across a considerable area. With the help of his men, the Spanish conquistador Pizarro invaded Inca Empire when it was in the midst of a war of succession between Atahualpa and the princes Huáscar.  

i r r e l e v a n t

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.