Answer:
The correct answer is: In all vertebrates.
Step-by-step explanation:
Hi! 
Let's solve this! 
 
Endocrine glands are responsible for the production and regulation of hormones. 
These glands are present in all vertebrates, including mammals and chordates. For example: humans have endocrine glands. 
 
We conclude that the correct answer is: In all vertebrates.