Finding Closest Value in a 2D Array

Consider the following findClosest method, which is intended to return the element in a 2D array mat that is closest in value to a given number val.

/** @return the element of 2-dimensional array mat whose value is closest to val */
public double findClosest(double[][] mat, double val)
{
    double answer = mat[0][0];
    double minDiff = Math.abs(answer - val);
    for (double[] row : mat)
    {
        for (double num : row)
        {
            if ( /* missing code */ )
            {
                answer = num;
                minDiff = Math.abs(num - val);
            }
        }
    }
    return answer;
}

Which of the following expressions can replace /* missing code */ so that the method works as intended?