Which of the Following Is a Positive Statement

Which of the following is a positive statement?

A) My economics class should last for two terms because it is my favourite class.
B) A 10 per cent increase in income leads to a 4 per cent increase in the consumption of beef.
C) Given their negative impact on productivity, the government should eliminate labour unions.
D) Taxes should be lower because then people get to keep more of what they earn.