Wooly mammoths became extinct thousands of years ago while other species of mammals that existed at that time still exist today. These other species of mammals most likely exist today because unlike the mammoths they

4. had certain inheritable traits that made them to survive

Explanation:

The options are:

1. produced offspring that all had identical inheritable characteristics

2. Did not face a struggle for survival

3. learned to migrate to a new environment

4. had certain inheritable traits that made them to survive

The correct option would be option 4.

This is law of natural selection at play. According to this law, organisms that are better suited to an environment survive, multiply, and pass their survival genes to their offspring. Those that are weakly adapted to the environment usually fade off the environment gradually.

Hence, other species of mammals exist today most likely because they had inheritable traits that made them to survive the changing environment while mammoths became extinct because they were poorly adapted to changing environment.

i think the answer is

mass

it would be c. xylem.