In the following passage some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.
Crude mineral oil comes out of the Earth as a thick brown or black liquid with strong ______. It is a ______ mixture of many different substances, each with its own ______ qualities. Most of them are combinations of hydrogen and carbon in varying ______. Such hydrocarbons are also found in other ______ such as bitumen, asphalt and natural gas.
found in other ______ such as bitumen

Options

A. relations
B. forms
C. things
D. varieties

Answer

B