Which of the following summarizes the main idea in paragraph 5? PLEASE HELP WITH THIS QUESTION

Paragraph 5 Says: Traits that are helpful in warm water may not be needed in the Arctic Ocean. Populations of a species living in different environments will develop different adaptations. For example, the ability to easily lose extra body heat would be helpful in a desert. This trait would be harmful in the Arctic. The camel's hump stores extra water for life in the desert. The hump would not be helpful to a rainforest monkey. Our environment will always change. Most of these changes take hundreds of years to occur. Scientists study the traits that have survived for hundreds of years. These adaptations show the power of short- and long-term environmental changes. They have shaped the world we live in today.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

the correct answer to this question is 2