Review the passage:
While Cynthia dressed for her sister's wedding, Murphy,
the golden retriever, ate the straps off the only shoes that matched Cynthia's
pale blue dress. Her replacement options were inappropriate. Like
rubber flip-flops, running shoes, fuzzy pink rabbit slippers, or brown leather
pumps.
You chose the first part, While Cynthia dressed for her sister's wedding, Murphy, the golden retriever, ate .... This part has a main clause: Murphy is the subject; ate is the verb. A fragment will not have a main clause.