True testing means that a serious effort is made to . Question 8 options:

be absolutely positively, without a shadow of a doubt, correct.

create experiments that support your hypothesis

falsify (“disprove”) each possible explanation.

complete testing that supports manufacturers claims, so you can cash in and make money.

Explanation:

This explanation is the opposite of true testing - a term known as falsifiability. Falsifiability, when it relates to science, refers to how it should be possible to prove a hypothesis or theory wrong. Thus, the point of testing for falsifiability is to test in which condition is the theory wrong.  

A term that might relate to the phrase ‘true testing’ used in the question would be testability. Which refers to the practice of testing a hypothesis or theory to see whether it is true or false.  

it's c (engineer's do their work with mechanical stuff not on any living being)