Which of These Is NOT Scientific

Multiple Choice

Which of these is NOT scientific?

A) A study determines differences in the species composition in two parks.
B) People are immunized with different vaccines to determine their relative effectiveness against the flu virus.
C) NASA sends tadpoles up in the space shuttle to see how gravity affects their development.
D) Consumers are asked which tomato variety produces the best-tasting spaghetti sauce.
E) A company uses different advertising methods for a product to determine which one produces the most sales.