Which of the following is a rational number?
Question:

Which of the following is a rational number?

(a) $\sqrt{5}$

(b) $0.101001000100001 \ldots$

(c) $\pi$

(d) $0.853853853 \ldots$

Solution:

Since, a number whose decimal expansion is terminating or non-terminating recurring is rational number.

So, 0.853853853… is a rational number.

Hence, the correct option is (d).