To which of the following situations does the Poisson distribution apply?

You count the number of times you have to take a particular unit before passing it$.$

You count the number of students out of a class of $150$ who want to register for the workshop group that is held right after the lecture.

You count the number of transactions on eBay between $10$:$00$ and $11$:$00$ on a Sunday.

You count the number of uranium atoms in a sample that decay within a given time interval.

none of the above