The difference between dry and wet clutches is as follows:

• A dry clutch has higher coefficient of friction. In wet clutches, the coefficient of friction is reduced due to oil.  The coefficient of friction for dry operation is 0.3 or more, while it is 0.1 or less for wet operation.
• The torque capacity of dry clutch is high compared with the torque capacity of wet clutch of the same dimensions due to the same reason mentioned in above point.
• For dry clutch, it is necessary to prevent contamination due to moisture or nearby lubricated machinery, by providing seals Such a problem is not serious in wet clutches.
• Heat dissipation is more difficult in dry clutches. In wet clutches, the lubricating oil carries away the frictional heat.
• Rate of wear is far less in wet clutches compared to dry clutches. The wear rate in wet clutches is about 1% of the rate expected in dry clutches.
• The engagement in wet clutch is smoother than in the case of dry clutch.
• In wet clutches, the clutch facings are grooved to provide for passage of lubricant. This reduces the net face area for transmitting torque.

Hence, the correct option is (B).