Option C — Only I, III and IV are correct.
Statements I and III were made compulsory by the Election Commission (filing income tax returns and holding organisational elections). Statement IV was made mandatory by the Supreme Court (filing affidavit disclosing criminal cases). Statement II (one-third women candidates) is only a suggestion, not yet made compulsory.
Source: How can parties be reformed?, Chapter 4
The key distinction here is between what has already been made compulsory (reforms that are in force) and what are merely suggestions (reforms proposed but not yet accepted). The textbook clearly states that the one-third women candidates rule is a suggestion, not a mandate — making Statement II incorrect. Examiners specifically test this distinction.