Casiopea said:
whl626 said:
In spite of his aged appearance, his movements were as spirited as a young man.
Young man is wrong and it should be replaced with ' youngster ' , right ?
What about?
His movements were as spirited as (that of) a young man's (movements).
All the best,
Aiya, I should have spotted it

We can't compare a movement with a person. That's illogical

But since the question only requires that we change the underlined word or phrase. I think
( His movements were as spirited as a young man's ) is fine, right ?