Answer is C. 8, 3, 6
To answer this, you must know the Triangle Inequality Theorem.
The two shortest sides when added together, must be greater than the longest side.
A. 2 + 4= 6 which can't work since it equals the longest side of 6
B. 4 +2=6 The sum would be less than 8, which doesn't work
C. 6 +3 = 9 the sum is greater than 8, which makes it a triangle
D. 3 +8 = 11 11 is less than 12