What Does It Mean That People Often Form Opinions on the Spot

What does it mean that people often form opinions on the spot?

A) Those opinions have essentially no meaning to the people who profess them.
B) People rely very heavily on their principles in formulating opinions.
C) People are sensitive to, and form their opinions based on, what they have recently
Seen or heard.
D) Their opinions are ill-informed and therefore are not counted in surveys.
E) We can only really tell what people believe by using sophisticated survey techniques.