Opposite actions combined in one split button

For the interface I'm working on, users can mark certain rows as "Verified", but they also have the option of marking them "Unverified". To do this, they select several rows by clicking on checkboxes and click on a button called, "Verify".

Should I include a separate button for "Unverify", like so:

Or should I instead use a split button and include "Unverify" as a sub-action of verify, like so:

A is clearer and I don't hide any action, but the objective is to get users to verify rows. I don't want users to accidentally be unverifying rows.

B hides one of the two actions and might be a problem for discovery, but is more space efficient and promotes the objective of verifying a row.

Thanks!