Answer:
B. locus ceruleus.
Explanation:
A nucleus present in the pons of brainstem responsible or involved in physiological responses to panic and stress is known as locus ceruleus. 
Basically, locus ceruleus is responsible for the primary production of norepinephrine in the brain. The nucleus transfers the norepinephrine to whole cerebral cortex along with various other structures like amygdala, cerebellum, hippocampus, and spinal cord. 
So, when there is a panic disorder due to norepinephrine dysregulation at the brainstem area which will be definitely locus ceruleus.  
 
        
             
        
        
        
Answer: The drive theory of motivation.
Explanation:
The drive threory of motivation is based on the principle that organisms have certain psycological or physiological needs (in this case, hunger). When those needs are not satisfied, a tension in the organism is produced, and with it a drive to seek the satisfaction of that need. 
Because the substance the rat recieves is nonnutritive (it doesn't reduce the rat's hunger), we can clearly see that the rat isn't performing the response because of this drive, seeking for the satisfaction of its hunger, but is motivated by another feeling. Therefore, this observation is problematic for the drive theory of motivation.
 
        
             
        
        
        
Answer:
The interphase stage.
Explanation:
During the interphase stage of mitosis, the cell does not divide and spends a big portion of the time at this stage. During that time, the cell synthesizes its DNA and doubles the cytoplasm.
 
        
                    
             
        
        
        
Options for the question have not been given. They are as follows:
type of soil
type of plants
exposure to sunlight
method for measuring the growth
Answer:
exposure to sunlight
Explanation:
A scientific experiment has an experimental group and a control group. Control group is included to omit any error in results due to the factors other than the variable factor. Experimental group is the one exposed to different levels of the variable factor.
Here, Carlo wants to determine the the effect of day length on plants' growth. The test variable here is thus the duration of sunlight. In experimental group, this duration will be changed to determine its effect. In control group it will be kept constant so that results from other factors can be excluded from the observed experimental result.