What is the smallest unit of an element that still can be identified as a specific

Option (a) is the correct answer.

Explanation:

It is known that when temperature is given in degree celsius and we want it to convert into kelvin then we need to add 273 into the given degree celsius.

For example, given temperature is .

Now, to convert it into degree celsius we need to add 273 into it as follows.

   Temperature in Kelvin = (72 + 273) K

                                         = 345 K

Thus, we can conclude that given temperature in Kelvin is 345 K.