A particle is describing circular motion in a horizontal plane in contact with the smooth inside surface of a fixed right circular cone with its axis vertical and vertex down. The height of the plane of motion above the vertex is h and the semivertical angle of the cone is `alpha`. The period of revolution of the particle:
| A. |
increases as h increases keeping `alpha` same |
 |
| B. |
decreases as h increases keeping `alpha` same |
| C. |
decreases as `alpha` increases keeping h same |
| D. |
None of these |