Berms are provided in canals if se are

The correct answer is Option B: Partly in excavation and partly in embankment.

In canal engineering, berms are provided when they are partly in excavation and partly in embankment. This is done to stabilize the slopes of the canal and prevent erosion. Berms act as horizontal shelves on the sides of the canal, providing support to the excavated and embanked portions.

Option A: Fully in excavation is incorrect because berms are not exclusively in excavation.

Option C: Fully in embankment is incorrect because berms are not exclusively in embankment.

Option D: All the above is incorrect because the correct condition for providing berms is when they are partly in excavation and partly in embankment, not fully in either.