I found this formula in an old book.
E = m · c²
It may be useful.
c = 3 x 10⁸ m/s
c² = 9 x 10¹⁶ m²/s²
4 x 10¹⁶ J = m · (9 x 10¹⁶ m²/s² )
m = (4 x 10¹⁶ J) / (9 x 10¹⁶ m²/s²)
m = 0.44 kg (choice-B)
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