The correct answer is 0, which means none of the options listed are correct. According to the question, the Congress took active steps in 1823 to eradicate untouchability from India. However, none of the options provided in the question accurately reflect the active steps taken by the Congress.

To clarify, the Congress did not make efforts to educate and mobilize opinion among caste Hindus, educate the `avamas` about the evils of untouchability, forcibly open the doors of temples for `avamas`, or petition the Government to pass laws declaring untouchability unlawful in 1823.

It`s important to note that this does not mean that the Congress did not take any measures against untouchability at all. It simply means that the options provided in the question are not accurate representations of the steps taken by the Congress in 1823.