The white regime in this context refers to the apartheid government in South Africa, which was characterized by systemic racial segregation and discrimination against the black majority. The decision to change its policies was influenced by several factors, including an increase in protests and struggles against apartheid, as well as the realization that repression was becoming increasingly difficult.

a) Increase in Protests and Struggles:
- The apartheid regime faced significant resistance from various sectors of society, including black South Africans, anti-apartheid activists, and international pressure.
- Protests, demonstrations, strikes, and other forms of resistance became more frequent and widespread, posing a challenge to the stability of the regime.
- These protests and struggles highlighted the dissatisfaction and demands of the black population, who were subjected to discrimination and limited opportunities under apartheid.
- The government recognized that maintaining the status quo would likely lead to further unrest and instability.

b) Government Realized that Repression was Becoming Difficult:
- The apartheid government relied heavily on repressive measures to maintain control and enforce racial segregation.
- However, as protests and international condemnation increased, the regime faced growing challenges in suppressing dissent and maintaining its grip on power.
- The use of violence and repression against peaceful protesters drew widespread criticism and tarnished South Africa's international image.
- The government realized that continuing with repressive policies would only exacerbate these challenges and further isolate the country.

c) Rise of Sympathetic Attitude in Government for the Blacks:
- Over time, some members of the white regime began to question the morality and sustainability of apartheid.
- There were individuals within the government who recognized the injustice and human rights violations inherent in apartheid.
- These individuals, along with external pressure and changing global attitudes towards racial discrimination, contributed to a shift in the government's thinking.
- The rise of a sympathetic attitude towards the plight of black South Africans within the government played a role in the decision to change policies.

d) Both (a) and (b):
- The decision to change policies was a result of both the increase in protests and struggles, as well as the acknowledgment that repression was becoming difficult.
- The combination of internal and external pressures, along with a changing political landscape, forced the apartheid regime to reassess its policies and consider alternative approaches.

In conclusion, the white regime in South Africa decided to change its policies due to a combination of factors, including an increase in protests and struggles against apartheid, the realization that repression was becoming increasingly difficult, and a rise in sympathetic attitudes towards the black population within the government. These factors collectively contributed to a shift in the government's thinking and ultimately led to the dismantling of apartheid.