13. Why is pure devotional service rare?

a) Because it can’t be achieved through one’s own effort
b) Because it can’t be achieved through one’s own effort & Krishna is reluctant to give it
c) Pure devotee of Krishna is reluctant to give it
d) Pure devotee of Krishna & Krishna are reluctant to give it

The correct answer is
b) Because it can’t be achieved through one’s own effort & Krishna is reluctant to give it