An insect crawls up a hemispherical surface very slowly (see the figure). The coefficient of friction between the insect and the surface is 1/3. If the line joining the centre of the hemispherical surface to the insect makes an angle \[\alpha \]with the vertical, the maximum possible value of \[\alpha \] is given by [IIT-JEE 2001]

• A. \[\cot \alpha =3\]
• B.    \[\tan \alpha =3\]
• C. \[\sec \alpha =3\]
• D.    \[\text{cosec}\,\alpha =\text{3}\]