It's clear from the passage that, in the event of an engine failure, ----.

All multi-engined aircraft are designed to keep flying
in the event of engine failure. Losing thrust from one
"side of an aircraft unbalances it and causes the
nose of the aircraft to turn in the direction of the failed
engine. Aircraft have a vertical stabilizer (the upright
at the back) to keep the aircraft's nose into the wind,
with a rudder attached to it for fine tuning. Moving the
rudder into the airflow creates a sideways force,
which turns the aircraft around its vertical axis. When
this is applied in the direction of the failed engine, the
force created by the rudder will counteract the turn
induced by the uneven engine thrust. The vertical
stabilizer and rudder are sized to control the uneven
thrust caused by an engine failure at the most
demanding limits or the flight envelope, as they must
be capable of generating powerful turning forces.