You will be given a definition of a task first, then some input of the task.
This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Passage: In the period before German colonisation, Samoa produced mostly copra. German merchants and settlers were active in introducing large scale plantation operations and developing new industries, notably cocoa bean and rubber, relying on imported labourers from China and Melanesia. When the value of natural rubber fell drastically, about the end of the Great War (World War I), the New Zealand government encouraged the production of bananas, for which there is a large market in New Zealand.[citation needed] Question: What product significantly dropped in price at the end of World War I?
Output:
natural rubber