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 ?

Adescription of a type of bio biotechnology (genetic engineering, cloning, or artificial section) one benefit or one risk for the individual (based on whether you are for or against it) one benefit or one risk for society (based on whether you are for or against it) one benefit or one risk for the environment (based on whether you are for or against it)