The u.s. citizenship and immigration service issues a rule. like the rules of other

B. the Code of Federal Regulations

Explanation:

The code of federal regulations consist of 50 areas that generally  controlled by Federal agencies. Violations of any of the codes written under the the Code of Federal Regulations will make people have to deal with FBI rather than local policies.

The rules written within the Code of Federal Regulations tends to be the ones that affect the situation on national level. This include things such as Immigration,  Agricultural regulation, Postal services, resources conservation, etc.

Gate theory                                        

Explanation:

Gate theory: The gate control theory of pain is developed by Patrick Wall and Ronald Melzack. This theory is referred to as the scientific theory that explains the psychological aspect of pain. The theory describes the pain as the outcome of the stability between the information passing through small and large nerve fibers into the spinal cord. It signifies the absence of pain because the gate is closed.

Melzack and Wall suggested that to rub injuries after they happen because that closes the gate and hence diminishes the pain.