oday I short 1 contract of the March 2020 E-mini S&P 500 future (whose underlying is 50*S&P 500 index. That is, one contract gives me the exposure of 50 times the change in S&P index. For more information, refer to http://www.cmegroup.com/trading/equity-index/us-index/e-mini-sandp500_contract_specifications.html). Suppose I put down an initial margin of 10,000. If tomorrow the future price goes up by 30 points. What is the balance of my margin account?

A. 8500

B. 9970

C. 10030

D. 11500