The correct answer is (b).
The Ranbir Penal Code (RPC) was the penal code applicable in the State of Jammu and Kashmir. It was enacted in 1882 and was based on the Indian Penal Code (IPC). However, the RPC had several provisions that were different from the IPC. These differences were mainly due to the special circumstances of the State of Jammu and Kashmir.
In 2019, the Government of India passed the J&K Reorganization Bill, 2019. This bill repealed the RPC and replaced it with the IPC. The IPC is now applicable in the entire State of Jammu and Kashmir.
The other options are incorrect. The J&K Reorganization Act, 2019, is an act of the Parliament of India that provides for the reorganization of the State of Jammu and Kashmir. The Constitution (Application to J&K) Order, 2019, is an order issued by the President of India that provides for the application of the Constitution of India to the State of Jammu and Kashmir. The Constitution (103rd Amendment) Act, 2019, is an act of the Parliament of India that amends the Constitution of India to provide for the reorganization of the State of Jammu and Kashmir.