What is a characteristic of straight chained alkanes?
they have one or more rings of carbon atoms.
they have carbon atoms that are double-bonded to other carbon atoms.
they have more than two carbons that are bonded to only one other carbon.
they have carbons bonded in a single row from one end of the molecule to the other end of the molecule.

Straight chains are by definition not cycles, so straight chain alkanes do not contain carbon rings. They are saturated hydrocarbons, meaning they only contain carbon and hydrogen, and the maximum number of C-H bonds are made, therefore there are non C=C double bonds. They do not necessarily need more than 2 carbons, for example ethane (C2H6) is a straight chain alkane, however they must contain carbons bonded in a single row from one end of the molecule to another, so the final answer is correct.

Hope this helps!

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