Correct Option (a):
A bill referred to a joint sitting of both Houses of Parliament is passed by a simple majority of members present and voting. Article 108 of the Constitution provides for a joint sitting, convened by the President, to resolve a legislative deadlock between the Lok Sabha and the Rajya Sabha on an ordinary bill. The decision in such a sitting is taken by a majority of the total number of members of both Houses present and voting.
Incorrect Options:
- Option (b) Three-fourths majority of members present and voting: This specific majority is not prescribed for passing a bill in a joint sitting of Parliament.
- Option (c) Two-thirds majority of the Houses: A two-thirds majority (special majority) is required for specific constitutional amendments (under Article 368), removal of judges, or certain resolutions, but not for passing an ordinary bill in a joint sitting.
- Option (d) Absolute majority of the Houses: An absolute majority (more than 50% of the total membership of the House) is not required for passing a bill in a joint sitting; a simple majority of those present and voting is sufficient.