The correct answer is option 3 - Madras Labour Union. This was India`s first trade union in the proper sense of the term.

To understand why it was the first trade union, let`s dissect the other options:

Option 1 - Bombay Labour Union: While the Bombay Labour Union was an important organization in the early labor movement in India, it was not the first trade union. It was established in 1890, several years after the Madras Labour Union.

Option 2 - Ahmedabad Labour Union: Similarly, the Ahmedabad Labour Union was an important organization in the labor movement in Ahmedabad, but it was not the first trade union in India. It was established in 1918, after the Madras Labour Union.

Option 4 - Allahabad Labour Union: The Allahabad Labour Union was established in 1918, making it a later organization than the Madras Labour Union. Therefore, it cannot be considered the first trade union in India.

Therefore, the correct answer is option 3, the Madras Labour Union, as it was the first trade union in India.