Sushma bought 6 tables and 12 chairs for Rs. 12,000. She sold the tables at a profit of 15% and the chairs at a loss of 10%. If her total gain was Rs. 300, then the total cost of the tables was:

• A. Rs. 4,800
• B. Rs. 5,000
• C. Rs. 6,000
• D. Rs. 5,400