Answer: B. The triangle in question is a right triangle.
Reason:
The sides are
Plug them into the equation below and simplify both sides
[tex]a^2+b^2 = c^2\\\\3^2+4^2 = 5^2\\\\9+16 = 25\\\\25 = 25\\\\[/tex]
Therefore, we have a right triangle. For more information, check out the converse of the pythagorean theorem.