Step 1: Understanding the Consumer Protection Act. 
  
The Consumer Protection Act, 2019, was passed by the Parliament of India to strengthen the rights of consumers and protect them against unfair trade practices. The law came into effect in 2020. 
Step 2: Analyzing the options. 
  
(A) 2018: Incorrect. The act was passed in 2019, not 2018. 
  
(B) 2019: Incorrect. Although the act was passed in 2019, it came into effect in 2020. 
  
(C) 2020: Correct. The Consumer Protection Act came into effect in 2020. 
  
(D) None of these: Correct. The act's effect started in 2020, making this the correct answer. 
Step 3: Conclusion. 
  
The correct answer is (D) None of these, as the law came into effect in 2020, although it was passed in 2019.