Under U.S. federal tax laws, investment earnings in qualified retirement plans O accrue on a tax-deferred basis, and participants pay taxes on these earnings when plan benefits are paid O are taxable when they are earned, and participants are not taxed on these earnings when plan benefts are paid O are taxable when they are earned, and participants pay taxes on these earnings again when plan benefits are paid O accrue on a tax-free basis, and participants do not pay taxes on these earnings when plan benefits are paid