《公路工程国内招标文件范本》规定，招标人在投标截止日前( )天可以用“补遗书”的方式修改招标文件。

A．15

B．21

C．28

D．30

Explain and distinguish between the following terms in relation to the doctrine of precedent in the Irish legal system:

(b) binding precedent and persuasive precedent. (6 marks)