Answer: B
Explanation: All you have to do to find out if an equation is balanced is count the number of atoms on each side. To be balanced, they must be equal.
In case you didn’t know: The number in front of an element or compound means that you will multiply. For instance, 2AlBr3 would have 2 Al atoms and 6 Br atoms. The subscript number just means how many atoms there are in that compound.