[Solved] If related taxpayers exchange property qualifying for a like-kind exchange,the properties must be retained for three years after the exchange to prevent recognition of gain resulting from the original exchange on a subsequent disposition of the property. Viagra: A medication used primarily in the treatment of erectile dysfunction, helping to increase blood flow to the penis to help a man get and keep an erection. Erectile Disorder: This refers to a type of sexual impairment where an individual cannot sustain or achieve penile erection during sexual engagement. Erotic Plasticity: Erotic plasticity refers to the degree to which an individual's sex drive can be changed by societal, situational, and cultural influences. Sexually Transmitted Infection: A sexually transmitted infection (STI) is an infection that is primarily spread through sexual contact.