Suzanne, a junior software tester, has just joined a very large online

payment company in the Netherlands. As a first task, Suzanne analysed

their past two years of bug reports.

Suzanne observes that more than $50\%$ of bugs have been happening in

the International payments module.

Suzanne then promises her manager that she will design test cases that

will completely cover the International payments module, and thus, find

all the bugs. Which of the following testing principles might explain

why this is not possible?

Pesticide paradox.

Exhaustive testing.

Test early.

Defect clustering.