Does the sentence "In 1913, Elmer McCollum discovered the first vitamins, fat-soluble vitamin A, and water-soluble vitamin B (in 1915; now known to be a complex of several water-soluble vitamins) and named vitamin C as the then-unknown substance preventing scurvy." provide a valid answer to the question "Which disease was vitamin C claimed to help prevent?" OPTIONS:
- yes
- no

A: yes

Does the sentence "The site allows users to upload, view, rate, share, and comment on videos, and it makes use of WebM, H.264/MPEG-4 AVC, and Adobe Flash Video technology to display a wide variety of user-generated and corporate media video." provide a valid answer to the question "How does youtube now operate as a business?" OPTIONS:
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A: no

Does the sentence "This type of testing focuses on the operational readiness of the system to be supported, and/or to become part of the production environment." provide a valid answer to the question "What is Operational Acceptance limited to while testing?" OPTIONS:
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A: no

Does the sentence "Blumenbach also noted the graded transition in appearances from one group to adjacent groups and suggested that "one variety of mankind does so sensibly pass into the other, that you cannot mark out the limits between them"." provide a valid answer to the question "What can one not mark between the variety of mankind?" OPTIONS:
- yes
- no

A:
yes