The average salary of a person for the months of February, March, April, and May is Rs. 12,000, and that for the month's March, April, May June is Rs. 13,000. If his salary for the month of June is Rs. 8,000, then what is his salary for the month of February?

• A. Rs. 4,500
• B. Rs, 5,500
• C. Rs, 4,000
• D. Rs. 5,000