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.

Example Input: Passage: Symbiosis played a major role in the co-evolution of flowering plants and the animals that pollinate them. Many plants that are pollinated by insects, bats, or birds have highly specialized flowers modified to promote pollination by a specific pollinator that is also correspondingly adapted. The first flowering plants in the fossil record had relatively simple flowers. Adaptive speciation quickly gave rise to many diverse groups of plants, and, at the same time, corresponding speciation occurred in certain insect groups. Some groups of plants developed nectar and large sticky pollen, while insects evolved more specialized morphologies to access and collect these rich food sources. In some taxa of plants and insects the relationship has become dependent, where the plant species can only be pollinated by one species of insect. Question: What did some plants produce when flowers became less simple?
Example Output: nectar and large sticky pollen

Example Input: Passage: A HDI of 0.8 or more is considered to represent "high development". This includes all developed countries, such as those in North America, Western Europe, Oceania, and Eastern Asia, as well as some developing countries in Eastern Europe, Central and South America, Southeast Asia, the Caribbean, and the oil-rich Arabian Peninsula. Seven countries were promoted to this category this year, leaving the "medium development" group: Albania, Belarus, Brazil, Libya, Macedonia, Russia and Saudi Arabia. Question: What number indicates the minimum score for a country to be considered a "high development" country?
Example Output: 0.8

Example Input: Passage: The late nineteenth century also brought the systematic study of color theory, and particularly the study of how complementary colors such as red and green reinforced each other when they were placed next to each other. These studies were avidly followed by artists such as Vincent van Gogh. Describing his painting, The Night Cafe, to his brother Theo in 1888, Van Gogh wrote: "I sought to express with red and green the terrible human passions. The hall is blood red and pale yellow, with a green billiard table in the center, and four lamps of lemon yellow, with rays of orange and green. Everywhere it is a battle and antithesis of the most different reds and greens." Question: When did the systematic study of color theory begin?
Example Output:
late nineteenth century