The correct option is
D D12 L29 W19 W13Common in
first and
third sentence is
Marble if seen on
left hand side while on
right hand side, it's
M16,
This means that M16 is the code used for Marble.
Similarly, C40 is for Current and N36 is used for Important.
Similarly, comparing second and fourth sentences, T25 stands for Quiz.
Now, as Insert is P20, so Window can either be W19 or I20.
For option A, Both these codes are used so this option is not applicable.
For option B, None of these two is used so this option gets invalid.
For option C, only W19 is present out of the two, so this is the correct option.
For option D, Both W19 and I20 are used so this option too gets ruled out.
Hence, option C is correct.