Meaning of 'they struck it very lucky'

[Terminator]

Test No. incompl/advan-57 "Lucky You", question 6

Last week they ......... it very lucky because they managed to win the lottery.

(a) hit
(b) struck
(c) knocked
(d) hammered

Test No. incompl/advan-57 "Lucky You", answer 6

Last week they struck it very lucky because they managed to win the lottery.

Correct answer: (b) struck

Hi! Help me, please! I didn't get it: "Last week they struck it very lucky..."
Thanks
Terminator

[Torsten]

Hi Terminator,

If you suddenly become rich or successful you strike it lucky. The expression might stem from the Casino where people try their luck and want to become rich.
You probably know 'Lucky Strikes', don't you?
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