Step 1: Understanding the Concept: Standardization marks are certifications issued by recognized bodies to assure consumers that a product conforms to specific quality and safety standards.
Step 2: Detailed Explanation: Assertion (A) is true; marks like ISI, Agmark, and FSSAI are implemented specifically to guarantee a baseline of quality and purity to the consumer.
Reason (R) states that Hallmark indicates the purity of 'only gold jewellery'.
This statement is false because the BIS Hallmark in India is used to certify the purity of both Gold and Silver jewellery.
The inclusion of the word 'only' makes the reasoning statement factually incorrect.
Step 3: Final Answer: Therefore, Assertion (A) is correct, but Reason (R) is entirely false.