An Upward Sloping Isoquant

An upward sloping isoquant:

A) can be derived from a production function with one input.
B) can be derived from a production function that uses more than one input where reductions in the use of any input always reduces output.
C) cannot be derived from a production function when a firm is assumed to maximize profits.
D) can be derived whenever one input to production is available at zero cost to the firm.
E) none of the above