Answer:  The correct option is

(C)  The triangle is not acute because 2² + 4² < 5².

Step-by-step explanation:  We are to select the statement that best explains the type of the triangle having lengths of three sides as 2 inch, 5 inch and 4 inch.

We know that a triangle with side lengths a, b and c (c > a, b)is

(i) an acute-angled if a² + b² > c², and

(ii) an obtuse-angled if a² + b² < c².

For the given triangle,

a = 2 inch, b = 4 inch  and  c = 5 inch.

So, we have

a^2+b^2=2^2+4^2=4+16=20,\\c^2=5^2=25.

Since,

20<25\\Rightarrow a^2+b^2<c^2,

so the given triangle is not acute, but obtuse.

Thus, the triangle is not acute because 2² + 4² < 5².

Option (C) is correct.