Final answer:
An antonym for the verb breach is 'seal', as breach means to break through and seal means to close off or make impervious.
Step-by-step explanation:
The antonym for the verb breach is b) seal. A breach involves breaking through, or opening up something such as a wall or barrier. To seal something, on the other hand, means to close it off or make it impervious. The options close and rupture are not antonyms for breach; close could be considered a more neutral term which can mean to bring something to an end, while rupture is actually a synonym of breach, meaning to break or burst.
An antonym for the verb BREACH is close. When you breach something, you are breaking or opening it. The opposite of that action would be to close it, which means to shut or seal it.