Living indicators are species that are sensitive to changes in the environment. For example air pollution can be monitored by looking at lichen, which are sensitive to sulphur dioxide in the air. The number of lichen at a particular location indicates how clear the air is. Similarly, mayfly larvae are good indicators for water pollution because they're sensitive to the concentration of dissolved oxygen in water.
Non-living indicators are things like satellites which can measure the temperature of the sea surface, weather stations that measure atmospheric temperature, rain gauges to measure rainfall, and dissolved oxygen meters to measure concentration of dissolved oxygen in water. 
        
             
        
        
        
Petroleum Products
Petroleum and its products are mainly composed of carbon polymers (chains), as the backbone, with different structural and functional groups. Plastic, for example, is made of polypropylene and polybutylene which is mainly made of carbon atoms, whose monomers are linked in a chain to form polymers that make up the products. 
Synthetic rubber on the other hand is made of copolymers of carbon and other addictives such as styrene. Synthetic fiber is made of nylon that is composed of a copolymer between carboxylic acid and amides.
        
             
        
        
        
Answer:
To produce white blood cells
Explanation:  is NOT a function of the liver.  
 
        
                    
             
        
        
        
Answer:
Enhancer sequence.
Explanation:
Enhancers may be defined as the transcription factors that are used to enhance or increase the activity of the gene. Enhancers bind with the transcription factors to regulate and increase its expression.
The mutation in the enhancers decrease the transcription of  of the other gene. These sequences lies far away from the transcription site but still known to increase the rate of transcription. Hence, the mutation has been done in the enhancer sequences.
Thus, the correct answer is option (b).