Bases loaded...less than 2 outs, pop on infield, bat called out, runner advances, tagged, out?

once the ball is hit in the air and it remains within the diamond, no runner is allowed to advance and the player who hit the ball is out. Even if the ball bounces, the base runners need to consider the situation as if the ball was caught. This is because if the fielder allowed the ball to drop on purpose, it may lead to unfair triple plays or double plays.