The correct answer is: Both A and R are true but R is not a correct explanation of A.
Rana Sanga lost the battle of Khanwa in the year 1527. This is a historical fact. However, the reason for his defeat is not clear. Some historians believe that Hasan Khan Mewati, an ally of Rana Sanga, betrayed him during the battle. However, there is no concrete evidence to support this claim. It is more likely that Rana Sanga was defeated due to a combination of factors, including the superior firepower of the Mughal army and the numerical superiority of the Mughal forces.
Even if Hasan Khan Mewati did betray Rana Sanga, this would not be a correct explanation of his defeat. The reason for a defeat is not always the actions of a single individual. In this case, Rana Sanga was defeated by a combination of factors, including the superior firepower of the Mughal army and the numerical superiority of the Mughal forces.