Answer:
The answer is "Yes, a copyright symbol must be added to protect the copyright".
Step-by-step explanation:
A copyright notice © is a symbol placed on copies of an intellectual property to protect it.
Plagiarism occurs when an intellectual property is used without acknowledging the author. this is an offence punishable by law.
It is possible to be safe without incorporating the copyright symbol but it is a gamble and here is why.
If the copyright notice is not included and someone plagiarizes innocently, it is called innocent infringement.
Innocent infringement suits in most cases does not favor the author. To avoid losing a suit over copyright protection issues, a copyright notice is a must.