When did President Mamnoon Hussain sign the bill merging FATA with KP:

The correct answer is 31-May-18. President Mamnoon Hussain signed the 25th Constitutional Amendment Bill into law on May 31, 2018. This landmark legislation officially merged the Federally Administered Tribal Areas (FATA) with the province of Khyber Pakhtunkhwa (KP), integrating the region into Pakistan's mainstream political and administrative structure.

• The dates 28-May-18, 29-May-18, and 30-May-18 are incorrect as the bill was signed on the last day of May 2018, marking a significant constitutional change.