Explanation:

All statements are correct.
China’s status as a ‘developing country’ at the World Trade Organization (WTO) has become a contentious issue with a number of countries raising concerns over the upper middle-income nation deriving benefits reserved for developing countries under WTO norms.

• Certain WTO agreements give developing countries special rights through ‘special and differential treatment’ (S&DT) provisions, which can grant developing countries longer timeframes to implement the agreements and even commitments to raise trading opportunities for such countries.
• WTO pacts are often aimed at reduction in government support to certain industries over time and set more lenient target for developing nations and grant them more time to achieve these targets compared to developed ones.
• The classification also allows other countries to offer preferential treatment.
• The WTO has not defined ‘developed’ and ‘developing’ countries and therefore member countries are free to announce whether they are ‘developed’ or ‘developing’.

Hence option 4th is correct.