Opt is related to Decide. Will is a type of Decide. Willing is a form of Will. 
Laugh is related to Happy. Happy is related to Face. Face is related to Stroke. 
Opt <--RelatedTo--> Decide <--IsA-- Will <--FormOf-- Willing 
Laugh <--RelatedTo--> Happy <--RelatedTo--> Face <--RelatedTo--> Stroke 