**I. Why the Article 48 of the Weimar Republic was considered harmful for the republic?**

The Article 48 of the Weimar Republic constitution granted the President of Germany emergency powers to govern the country in times of crisis. While it was intended to provide a mechanism for the government to respond effectively to emergencies, it ultimately posed significant threats to the stability and functioning of the republic. The harmful aspects of Article 48 can be summarized as follows:

**a) It gave too much power to the trade unions:**

This statement is incorrect. Article 48 did not grant power to trade unions. It primarily vested emergency powers in the President of Germany.

**b) It gave the president power to impose emergency, suspend fundamental rights and rule by decree:**

This statement is correct. Article 48 gave the President the authority to impose a state of emergency, suspend fundamental rights, and rule by decree. While these powers were intended to address urgent situations such as rebellion or insurrection, they allowed the President to bypass the parliamentary system and make decisions unilaterally. This undermined democracy and created potential for abuse of power.

**c) It provided a complex system of proportional representation:**

This statement is incorrect. Article 48 did not deal with the system of proportional representation. It focused on emergency powers of the President.

**d) All the above:**

This statement is partly correct. The correct answer is a mixture of options b and c. Article 48 of the Weimar Republic was considered harmful because it gave the President extensive powers to impose emergency measures, suspend fundamental rights, and rule by decree. These powers undermined the democratic system and allowed for potential abuse. However, the provision of a complex system of proportional representation was not directly related to the harmful nature of Article 48.

In conclusion, Article 48 of the Weimar Republic constitution was considered harmful primarily because it granted the President vast emergency powers, enabling the suspension of fundamental rights and rule by decree. This compromised the democratic principles of the republic and increased the likelihood of authoritarianism.

(b) is the correct answer.