Final answer:
Knights were identified by their own heraldry, which was displayed on shields, and banners, and could extend to swords, making heraldry, shields, and swords the correct answers to fill in the blanks.
Step-by-step explanation:
Each knight was identified by his own heraldry, which was the system of designating a particular pattern and colors to an individual or family. This personal or familial symbol was displayed on their shield and was also present on other items, such as the knight's banners, and could even extend to other possessions like swords or horses.
The correct phrase to fill in the blanks from the options provided would be: Each knight had his own heraldry that identified him. The pattern and colors of this were on his shield and any other items that belonged to the king. Knights even had swords with this on them, making option B the correct choice.