${?}_{{?}_{{?}_{?}}{?}_t\text{e}\text{s}\text{t}\text{i}\text{n}\text{g}is\text{t}\text{h}\text{e}\text{d}\text{e}\text{t}\text{e}\text{r}\text{m}\text{i}\text{n}\text{a}\text{t}\text{i}\text{o}\text{n}of\text{w}\text{h}\text{e}\text{t}\text{h}\text{e}\text{r}\text{a}\text{p}\text{r}\text{o}\text{d}\text{u}\text{c}\text{t}is\text{b}\text{e}\text{i}\text{n}\text{g}\text{b}\text{u}\text{i}\text{l}\text{t}\text{c}\text{o}\text{r}\text{r}\text{e}\text{c}\text{t}\text{l}\text{y}}$

Question $9$ options:

Validation

Assertion

Assurance

Verification