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: In its early years Universal released three brands of feature films Red Feather, low-budget programmers; Bluebird, more ambitious productions; and Jewel, their prestige motion pictures. Directors included Jack Conway, John Ford, Rex Ingram, Robert Z. Leonard, George Marshall and Lois Weber, one of the few women directing films in Hollywood.:13 Question: What sort of films were produced by Red Feather?
Example Output: low-budget programmers

Example Input: Passage: Whitehead pointed to the limitations of language as one of the main culprits in maintaining a materialistic way of thinking, and acknowledged that it may be difficult to ever wholly move past such ideas in everyday speech. After all, each moment of each person's life can hardly be given a different proper name, and it is easy and convenient to think of people and objects as remaining fundamentally the same things, rather than constantly keeping in mind that each thing is a different thing from what it was a moment ago. Yet the limitations of everyday living and everyday speech should not prevent people from realizing that "material substances" or "essences" are a convenient generalized description of a continuum of particular, concrete processes. No one questions that a ten-year-old person is quite different by the time he or she turns thirty years old, and in many ways is not the same person at all; Whitehead points out that it is not philosophically or ontologically sound to think that a person is the same from one second to the next. Question: Whitehead's main philosophy on humans changing is what?
Example Output: each thing is a different thing from what it was a moment ago

Example Input: Passage: Grape juice is obtained from crushing and blending grapes into a liquid. The juice is often sold in stores or fermented and made into wine, brandy, or vinegar. Grape juice that has been pasteurized, removing any naturally occurring yeast, will not ferment if kept sterile, and thus contains no alcohol. In the wine industry, grape juice that contains 723% of pulp, skins, stems and seeds is often referred to as "must". In North America, the most common grape juice is purple and made from Concord grapes, while white grape juice is commonly made from Niagara grapes, both of which are varieties of native American grapes, a different species from European wine grapes. In California, Sultana (known there as Thompson Seedless) grapes are sometimes diverted from the raisin or table market to produce white juice. Question: What types of grapes are commonly used to make white grape juice?
Example Output:
Niagara grapes