Animals that put all their weight on one toe are able to run more quickly across smooth, solid ground. Shortly after grasslands appeared, horses adapted to eating grass. How would running quickly probably have been an advantage to the horse's ancestors?

i believe it is a.) released into

explanation:

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.