Attributes of feudalism include which of the following? select all that apply. serfs worked land owned by the king. through investiture, a vassal was beholden to a lord to do his dirty work. knights served large landholders by defending their lands in exchange for a fief. lords, vassals, knights, and serfs all worked interdependently to ensure the safety and financial viability of the whole on equal footing. a serf would work the land, a knight would protect it, a vassal would govern it and the lord would reap the benefits but also suffer the consequences if not managed well.