Respuesta :

6.244 because 8 squared minus 5 squared equals 39. the sr of 39 is 6.244
Just apply the Pythagoras Theorem, 

AC² + BC² = AB²

AC² + 5² = 8²

AC² = 64 - 25

AC = √39

AC = 6.244

In short, Your Answer would be: Option E) None of the above

Hope this helps!