I think the correct answer is a
The answer to this question would be: <span>track changes in weight over time.
When a person consumes an adequate amount of calorie, the weight wouldn't be changed. If the calorie is not enough, the body will burn the fat stored to fulfill the energy required, result in reduced body weight. If the calorie is too much, the body will store the excess calorie as fat, results in increased body weight.</span>
The correct substitutes would be " A. Ellos lo compraron
In English, Ellos compraron El Reloj Pulsera means : They (masculine) bought the watch
Reloj : Masculine singular Pronoun, which means that the objective pronoun should be : LO
Hope this helps
Answer:
Attached is an image go help you with this.
Storing nutrition and keeping warm, A good example would be walruses since they have no fur to keep warm