详细解释:a. 只由雇主缴纳、雇员无需缴纳的(养老金的积储办法)
详细解释：
non.con.trib.u.to.ry
adj.（形容词）Of or relating to a pension plan in which participating members or employees are not required to support the plan with their own contributions.无贡献或不涉及贡献的：属于或关于不要求参与者或被雇者用他们自己的贡献物来支持的年金方案的