You can’t expect people to sit and monitor these forums 42/7 for free, can you?
Now to your question – product.options is already an array, so splitting it will do nothing good.
I also see no reason to use handle since what it does among other things is down-case, replace non-ascii characters with best ascii matches and replace spaces, etc with dashes.
You’d only need to do {{ product.options | join: " / " }} to get what you want.