With reference to Vaccine Vial Monitors(VVM) being used on vaccine vials, which of the following statements is/are correct?
1. It gives information about heat exposure over a period of time
2. It directly indicates vaccine potency
Select the correct answer using the code given below:
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2