The provincial government system in PNG was mainly introduced after Papua New Guinea independence to:

Here are the answers to the questions:

1) The provincial government system in PNG was mainly introduced after Papua New Guinea independence to:
B. Promote decentralization and reduce regional tensions.

The provincial government system was established to devolve power from the central government to the provinces, aiming to address regional demands for greater autonomy and mitigate tensions among different regions.

2) Which region strongly pushed for autonomy, influencing the creation of the provincial government system?
C. Bougainville.

Bougainville's strong desire for greater self-governance and its secessionist movements were significant factors that influenced the establishment of the provincial government system in Papua New Guinea.

3) The 1976 Organic Law on Provincial Government was mainly designed to:
C. Establish provincial governments and give them authority.

This law provided the legal framework for the creation of provincial governments, defining their powers, functions, and responsibilities, thereby formalizing the decentralization of governance.