Here is the item:
Latoya would have swum farther, but a cramp stang her side, so she rode a wave into shore and spent the afternoon watching handsome young men parading on the beach.

The second verb, stang, is the problem. As you know, the sentence requires the simple past. Stung is the correctly spelled form.

Verb Simple
Present
Simple
Past
Past
Participle
sting sting(s) stung stung

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