Take another look at the sentence:
Melissa dug in her heels and __________ the leash with both hands; Mellie, her Labrador retriever, saw children playing Frisbee down the street and wanted desperately to chase the flying red disk.
The sentence requires the simple past of hold, an irregular verb. Held is the simple past form.
|Verb||Simple Present||Simple Past||Past Participle|
Holded, the form you chose, is a spelling error. Before you continue, review the rules for irregular verbs.