Custody is defined by the Supreme Court as happening when:

A person has been taken into "custody".
A person has been formally arrested.
A person has been deprived of his freedom of action in any significant way.
All of the above.

all the above

To determine the correct answer to this question, we can break it down and explain the options provided.

Option 1: "A person has been taken into 'custody'."
Being taken into custody implies that an individual has been apprehended or detained by law enforcement officials. However, it does not necessarily mean that they have been formally arrested or deprived of their freedom of action in a significant way.

Option 2: "A person has been formally arrested."
Formal arrest is a legal process where a person is taken into custody, typically accompanied by the presentation of a warrant or probable cause. While formal arrest is one way to define custody, it is not the only way.

Option 3: "A person has been deprived of his freedom of action in any significant way."
This definition of custody encompasses situations where a person's freedom of action has been significantly limited, even without formal arrest. It can include scenarios such as being detained, restrained, or held against one's will.

Option 4: "All of the above."
Since all three options - being taken into "custody," being formally arrested, and being deprived of freedom of action in a significant way - are valid definitions of custody, the correct answer is "All of the above."

Therefore, the Supreme Court defines custody as happening when a person has been taken into "custody," has been formally arrested, or has been deprived of his freedom of action in any significant way.