1. **State the problem:** Juan's savings account balance quadrupled during the year. After withdrawing 300, the balance was 400. We need to find the balance before it quadrupled. 2. **Define variables:** Let the initial balance before quadrupling be $x$. 3. **Write the equation:** After quadrupling, the balance is $4x$. Then Juan withdraws 300, so the balance becomes $4x - 300$. 4. **Set up the equation with the given final balance:** $$4x - 300 = 400$$ 5. **Solve for $x$:** $$4x = 400 + 300$$ $$4x = 700$$ 6. **Divide both sides by 4:** $$x = \frac{700}{4}$$ $$x = \cancel{\frac{700}{4}} = 175$$ 7. **Interpretation:** The initial balance before it quadrupled was 175. **Final answer:** B. 175