The correct answer is: C. Rs. 1 lakh.
The Bihar State Government has announced a cash reward of Rs. 1 lakh to the SC/ST, OBC students after qualifying the UPSC preliminary exam. This is a great initiative by the government to encourage students from these communities to pursue a career in civil services.
The cash reward will be given to the students who qualify the UPSC preliminary exam in the first attempt. The students will have to submit a proof of their SC/ST or OBC status to the government in order to claim the reward.
This is a very positive step by the government and it is sure to motivate students from these communities to work hard and achieve their dreams. The government should also consider providing financial assistance to these students to help them cover the expenses of their preparation for the UPSC exam.
The other options are incorrect because they are not the amount of cash reward given by the Bihar State Government to the SC/ST, OBC students after qualifying the UPSC preliminary exam.