This is true everyone i know uses it all the time
According to your definition: Modesty means the quality or state of being unassuming or moderate in the estimation of one's ability.
And, Now we require to define it in our way, and in easy language.....So, We can say that !!

❍ Modesty - It is the quality of not being much proud or confident about ourselves or on our abilities. Let's see some examples to capture properly:
- She accepted the award with modesty.
- There was no false modesty in her victory speech.
- Because of her modesty, the young woman was uncomfortable wearing a bathing suit in public.
- Many religions emphasize modesty and being reserved in appearance.
<u>━━━━━━━━━━━━━━━━━━━━</u>
The correct answer should be C) bias
If the person works for a national energy company there is high chance that the person would be a bit biased towards installing the new systems. This should definitely be checked.