This year will have a february 29th if, and only if, this is a leap year. which word phrase in the statement makes this a biconditional ?

Which best describes this behavior? it is beneficial only to the males that do not fertilize eggs. it is beneficial only to the female workers that are not fertilized. it is beneficial to each one of the individual colony members. it is beneficial to the whole species, but not to all of the individual members.