Terminally ill California residents may now legally take medicine to end their lives, thanks to a new law that goes into effect Thursday

Under the "End of Life Option Act," California has become the fifth state in the nation to create a legal process for patients to obtain aid in dying.

And how the law fares in such a large and diverse state could shape whether this controversial option gains traction in the rest of the nation.

Advocates say people should have the right to decide whether they want "aid in dying," while opponents argue patients could feel pressure to take their own lives.

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