Look for the largest square factor of 24. Since 24 = 4 × 6 and √4 = 2, we get √24 = 2√6. To simplify a surd, split the number under the root into a perfect-square factor and the remaining factor. Take the square root of the perfect square outside the radical. The expression is simplified when no square factor greater than 1 remains under the root. The correct answer is 2√6, which matches the calculation or reasoning shown.