Shopping online can save much time as you _____ go to a shop or walk around crowded shopping centers.[ ]

A. don't have to

B. oughtn't to

C. won't

D. mustn't

绿色食品标准是绿色食品认证和管理的依据和基础；是由农业部发布的推荐性农业行业标准（NY/T），是绿色食品生产企业（）的标准。