Which of the following is NOT a characteristic of alkanes?

Alkanes are a class of hydrocarbons that are defined by specific characteristics. They are saturated hydrocarbons, which means that they contain the maximum possible number of hydrogen atoms for a given number of carbon atoms. This saturation is achieved because alkanes only have single bonds between their carbon atoms.

Option A indicates that alkanes contain double bonds; however, this statement is incorrect since alkanes exclusively feature single bonds and do not have any double or triple bonds in their structure. Consequently, this aspect of alkanes makes them less reactive than alkenes, which do include double bonds and hence can participate in reactions that alkanes cannot.

Hence, the correct answer identifies a fundamental misconception about alkanes, highlighting that they do not possess double bonds. This understanding reinforces the distinct properties that characterize alkanes compared to other hydrocarbons, such as alkenes.