The correct option is B 3, 4, 5
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->
For a geometrical figure to be a triangle, the sum of lengths of any two sides must be greater than the third side. Otherwise, a triangle cannot be formed.
Here, other than sides (in cm) 3, 4, and 5, none of the other sets satisfy the above condition.