Answer:
The answer to your question is letter B.
Step-by-step explanation:
The correct answer is letter B because both Copper and Iron as reactants have an oxidation number of zero and when they have reacted their oxidation numbers would be different from those.
A redox reaction is a reaction that involves a transfer of electrons from one atom to another and the oxidation numbers of the reactants are different from the oxidation numbers from the products.
Answer:

Step-by-step explanation:

Let's solve your equation step-by-step.
6.75+38x=1314
Step 1: Simplify both sides of the equation.
38x+6.75=534
Step 2: Subtract 6.75 from both sides.
38x+6.75−6.75=534−6.75
38x=132
Step 3: Multiply both sides by 8/3.
(83)*(38x)=(83)*(132)
x=523
Answer:
x=1713