Step 1: Understanding the Question:
The question asks why liberalisation measures are also called economic reforms. A reform means a wide change that reshapes something.
Step 2: Key point from the passage.
The passage says that since July 1991 there were reforms in all major sectors, such as agriculture, industry, trade, foreign investment, technology, public sector and financial institutions.
Step 3: Check option 1.
The passage lists many sectors, not only tax. So this is wrong.
Step 4: Check option 2.
The reforms covered all the main sectors of the economy, which is why they are called reforms. This is right.
Step 5: Check option 3.
The public sector is only one item in the list. So saying only the public sector changed is wrong.
Step 6: Check option 4.
The passage says the aim was benefit to the Indian economy as a whole, not only to multinational firms. So this is wrong.
Final Answer:
They are called reforms because they restructured all major sectors, option 2.
\[ \boxed{\text{Option 2}} \]