Let a, b and c
The lengths of triangle
The sum of two sides will always be larger than the other side.
Then,
| b - c | < a < b + c
| a - c | < b < a + c
| a - b | < c < a + b
To the question A)
a = 83
83 < 40 + 34
83 < 74
False!
____________
Letter B)
a = 51
51 < 33 + 5
False!
___________
Letter C)
a = 50
50 < 31 + 19
False!
____________
Now on the letter D)
a = 29
29 < 18 + 13
29 < 31
It is correct!
Then,
The letter D) would be the answer!
