Her confidence shaken, Sheryl spelled the word again.

“Her confidence shaken” is an absolute phrase: it contains a noun (“confidence”) and a participial adjective (“shaken”), but it does not form a complete sentence on its own. It adds background information about Sheryl as she spelled the word again. An appositive instead renames a noun, so choice B, absolute, is correct.

AI-written and checked against the verified answer.