The idiom 'hit pay dirt' is used to mean -

A great attempts but insignificant achievement

B to make furtile attempts

C to end up in failures after great labour

D to achieve something valuable after an arduous search

Correct Answer: Option D

hit pay dirt =make valuable discovery -দীর্ঘ /কষ্টকর অনুসন্ধানের পর মূল্যবান কোন কিছু অর্জন করা ।