Answer:

Step-by-step explanation:
Here, we want to check if the equation of the reaction is balanced or not
Now, for a balanced equation of reaction, the number of atoms of the individual elements on both sides of the equation is equal
Now, let us check the atoms:
We have 1 Sr on both sides
We have 1 SO4 on both sides
We have 1 Mg on both sides
We have 2 OH on both sides
From what we can see, the equation of the reaction is balanced
Thus, the correct answer choice is B