What is unit testing?

Group of answer choices

Ensuring a program is not one large function but rather consists of numerous smaller functions $($units$)$

Checking that the integer values of a function use proper units $($yards$,$ meters, etc.$)$

Dividing larger function parameters into several smaller parameters known as units

Individually testing a small part $($or unit$)$ of a program, typically a function, using a separate program called a test harness