The given curve is
Differentiating both sides with respect to x, we get
At (0, 0), we have
We know that, if , then the tangent is parallel to the y-axis.
Now,
So, the tangent to the given curve at (0, 0) is parallel to the y-axis.
Thus, the curve has at (0, 0) a vertical tangent.
Hence, the correct answer is option (a).