When a Bill is referred to a joint sitting of both the Houses of the Indian Parliament, it has to be passed by a simple majority of members present and voting.

Option 1 states that a simple majority of members present and voting is required for the Bill to be passed. This means that if more members present and voting are in favor of the Bill than against it, the Bill will be considered passed.

Option 2 states that a three-fourths majority of members present and voting is required. However, this is not correct as the Bill only needs a simple majority, not a larger majority like three-fourths.

Option 3 states that a two-thirds majority of the Houses is required. This is also not correct because the Bill only needs a simple majority of members present and voting, not a two-thirds majority of the entire Houses.

Option 4 states that an absolute majority of the total membership of the Houses is required. However, this is also incorrect as it does not accurately reflect the requirement for a simple majority of members present and voting.

Therefore, the correct answer is option 1, which is a simple majority of members present and voting.