When $$3^{21684}$$ is divided by 5, the remainder is:

Correct option is A

​$$\text{divisible rule of 3 -}$$​​

​$$\frac{21684}{4}, \quad \text{Remainder} = 0$$

$$3^4 = 81$$

$$\text{Now, } \frac{81}{5}, \quad \text{Remainder} = 1$$​​​​