The correct option is D All are regular die
The sum of digits on the opposite faces of a regular die is 7.
On the first die,
1 is opposite to 6, so 1 + 6 = 7
2 is opposite to 5, so 2 + 5 = 7
3 to opposite to 4, so 3 + 4 = 7
So, in the first option, the given option is a regular die.
On the second die,
1 is opposite to 6, so 1 + 6 = 7
2 is opposite to 5, so 2 + 5 = 7
3 to opposite to 4, so 3 + 4 = 7
So, in the second option, the given option is a regular die.
On the third die,
1 is opposite to 6, so 1 + 6 = 7
2 is opposite to 5, so 2 + 5 = 7
3 to opposite to 4, so 3 + 4 = 7
So, in the third option, the given option is also a regular die.
So, all three die given are regular die.
Thus, all die are regular die.