Fill the operation signs "$$+$$" or~"$$-$$" in the squares below to make the equation true.  $$4\square 3\square 2\square1=8$$ 
选项为:A:$$+$$, $$-$$, $$+$$  B:$$-$$, $$+$$, $$-$$  C:$$+$$, $$+$$, $$-$$  D:$$+$$, $$+$$, $$+$$  E:$$-$$, $$-$$, $$-$$  请回答其中一个选项.