Solution
Expression : $$3^{1001} \times 7^{1002} \times 13^{1003}$$
= $$3^{4k+1} \times 7^{4k+2} \times 13^{4k+3}$$
Unit's digit will be same as unit digit of $$(3)^1\times(7)^2\times(3)^3$$
Only unit digit considered = $$3\times9\times7=9$$
=> Ans - (D)
