$.extend to merge objects

$.extend to merge objects

I have an object like this:
  1. config = { options: [['Option1'], ['Option2', 'Option3', 'Option4'], ['Option5', 'Option6']] };

I then have an html element with a data attribute like this:

  1. data-extraoptions="[['Option7','Option8','Option9'],['Option10','Option11']"

How can I convert data-extraoptions into an object and then merge into my config variable?

I've tried just using a comma delimited string in data-extraoptions and using the split function, then using $.extend(true, config, [extraOptions]);, but doing so removes whatever is in 'Option1' above. It also doesn't allow me to group the items together as needed.

I've also tried parseJSON() with no luck.

Any ideas?