I always keep a tin of biscuits in my room, girls.

• A. The matron said that she always keeps a tin of biscuits in her room.
• B. The matron informed the girls that she always kept a tin of biscuits in her room.
• C. The matron told the girls that she would always keep a tin of biscuits in her room.
• D. The matron told the girls that she had kept a tin of biscuits in her room.