Take another look at the sentence:
Jennifer has discovered that hanging clothes outside to dry has its disadvantages. Recently, a spider crept into a pair of her jeans and __________ a day biting the "intruder"—Jennifer's bare leg—that had invaded the arachnid's new home.
The sentence requires the past tense of spend, an irregular verb. Spent is the simple past form.
|Verb||Simple Present||Simple Past||Past Participle|
Spended, the form you chose, is a spelling error. Before you continue, review the rules for irregular verbs.