Which of these is an opinion?
A. Biofuels are sustainable because they are made from
various types of plants.
B. Jatropha oil blends should be used by every major airline
after the year 2013.
C. Biofuel was used in a successful two-hour test flight in
New Zealand.
D. Jatropha plants can be grown on land that is not suitable
for food crops.