Read the following passage carefully and answer the given questions. Certain words/phrases are given in bold to help you locate them while answering some of the questions.
Which of the following factors is responsible for a rise in speculation in crude oil markets?
A. OPEC has not been able to restrict the oil output and control prices.
B. The supply of oil has been rising to match demand.
C. The existence of a large number of oil futures and oil contracts.