In substitution type of questions, some particular objects are assigned code names. Then a question is asked that is to be answered in the code language.
If cushion is called pillow, pillow is called mat, mat is called bedsheet and bedsheet is called cover, which will be spread on the floor ?
'Mat' will be spread on the floor.
But 'mat' is called 'bedsheet'.
So, a 'bedsheet' will be spread on the floor.