GMAT Sentence Correction (SC) | Re: All smoke alarms in one's house should be tested once a

A) All smoke alarms in one's house should be tested once a month, and their batteries should be replaced annually-Sentence Looks good as is- So hold.

B) All smoke alarms in one's house should be tested once their batteries are replaced annually-No Punctuation- Makes it as a run on sentence. Also changes the meaning- Eliminate.

C) One should test all smoke alarms in one's house once a month and annually replace their batteries once ayear- Annually & Once a year- Redundant- Eliminate