Change the sentence into exclamatory sentence.
It was a very long and colourful journey.

The correct answer is Option C (What a very long and colourful journey it was!).

Key Points:
• The question tests the transformation of an assertive sentence into an exclamatory sentence.
• Rule: When an assertive sentence contains the article 'a' or 'an' before an adjective + noun structure, the exclamatory sentence must begin with 'What a/an'.
• Original: It was a very long and colourful journey.
• Exclamatory: What a long and colourful journey it was! (Note: 'very' is generally removed in standard transformation, but in the given MPSC options, Option 3 retains it to fit the 'What a' structure optimally among the choices).
• Options 1 and 2 just add an exclamation mark to an assertive sentence. Option 4 is an interrogative sentence.
• Key Takeaway: Assertive sentences with 'a/an' transform into exclamatory starting with 'What a/an...!'