Copper is reduced from the ______ copper ion to the copper ion when reducing sugars are present with Benedict's test, which turns the solution from a _______ color to a____ color.
a) Cu²⁺, Cu⁺, blue, red
b) Cu⁺, Cu²⁺, red, blue
c) Cu⁺, Cu²⁺, blue, red
d) Cu²⁺, Cu⁺, red, blue