The correct options are
A Post-independence, 50% of land area of undivided Punjab became part of India while the rest merged with Pakistan.
B Around nine princely states of Punjab was merged to form the Patiala and East Punjab States Federation (PEPSF).
C As per the recommendations of the Shah Commission, the state of PEPSF was renamed as United Punjab in 1956.
D On 1 November, 1966, United Punjab was split into Punjab, Haryana, and Uttar Pradesh along linguistic lines.
After India achieved Independence in 1947, 34% of land area of undivided Punjab became part of India while the rest merged with Pakistan. In 1948, the princely districts of Patiala, Nabha, Malerkotla, Jind, Kapurthala, Faridkot, Nalagarh, and Kalsia were merged together to form the Patiala and East Punjab States Union (PEPSU). It was renamed as United Punjab in 1956. Thereafter, in 1966, the state was split into Punjab, Haryana, and Himachal Pradesh on linguistic grounds.
Thus, all of the above given statements provide incorrect information about the formation of Punjab.