Take another look at the sentence:
Thrashing on the surface of the lake, a huge catfish __________ Reggie's fishing pole almost to the point of breaking. Reggie fought on, images of fried fillets making his mouth water.
The sentence requires the simple past of bend, an irregular verb. Bent is the simple past form.
|Verb||Simple Present||Simple Past||Past Participle|
Had bended, the form you chose, is a spelling error. Before you continue, review the rules for irregular verbs.