Step 1: Read the clue first. Look for the sentence in the passage that begins with the word "Third". It says mass communication needs a formal organisation because of big capital, production and management demands.
Step 2: Test choice 1. Choice 1 talks about audience size. The passage never uses audience size as the point of difference, so it fails.
Step 3: Test choice 2. Choice 2 repeats the idea of a formal structural organisation for capital, production and management, which is the third point of the passage, so it fits.
Step 4: Test choice 3. Choice 3 speaks of skills. No sentence in the passage gives skills as the reason, so it fails.
Step 5: Test choice 4. Choice 4 speaks of training. This is also absent from the passage, so it fails.
Final Answer: Choice 2 matches the third point of the passage, so the answer is formal structural organization. \[ \boxed{\text{Option 2}} \]
