Read the sentences.

When bricking a building, masons must fit the bricks together. Sometimes, masons slice bricks in half for a better fit.

Which is the best way to combine the sentences?

When bricking a building, masons must fit the bricks together; Sometimes they slice bricks in half for a better fit.

When bricking a building, masons must fit the bricks together; sometimes they slice bricks in half for a better fit.

When bricking a building: masons must fit the bricks together; sometimes they slice bricks in half for a better fit.