The correct option is D 28m
There are 28 apples in 1 bag.
Number of apples in 1 bag =28
Number of apples in 2 bags =2×28=56
Number of apples in 3 bags =3×28=84
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Similarly,
Number of apples in m bags =m×28=28m
The number of apples in m bags would be 28m. Therefore, option (d.) is the correct answer.