Answer:
D. 4 centimeters, 6 centimeters, 9 centimeters
Step-by-step explanation:
Considering side length for forming a triangle, most of the time it is about Triangle Inequality Theorem, which for 3 sides length a,b,c, it must satisfy the following set of inequalities:
[tex]a+b>c\\a+c>b\\b+c>a[/tex]
By checking each of them only D satisfy:
[tex]4+6=10>9\\6+9=15>4\\9+4=13>6[/tex]
For simplicity you only have to check if the two shortest sides add up to be larger than the longest side:
[tex]4+6>9[/tex]