Consider the equation: A+3B--->4C. If 3.0 moles of A is reacted with 6.0 moles of B, which of the following is true after the reaction is complete? Explain your answer.

a.) A is the leftover reactant b/c you only need 2 moles of A and have 3.

BA is the leftover reactant b/c for every 1 mole of A, 4 moles of C are produced.
CB is the leftover reactant b/c you have more moles of b than A.
DB is the leftover reactant b/c 3 moles of B react with every 1 mole of A.
ENeither reactant is leftover.