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The mass of solid lead would displace exactly 234.6 liters of water should be <span>2,674,440</span>
        
                    
             
        
        
        
Answer:
V ∝ abc
Explanation:
This task is a joint variation task involving only direct proportionality:
Direct variation is one in which two variables are in direct proportionality to each other. This means that as one increases, the other variable also increases and vice - versa.
Joint variation is one in which one variable is dependent on two or more variables and varies directly as each of them. 
In this exercise:
If a ∝ b and a ∝ c, then a ∝ bc
Taking the above three proportionalities, 
V ∝ a ∝ b ∝ c
V ∝ a ∝ bc
V ∝ abc
 
        
             
        
        
        
Answer: the best statement is 1 (Vitamin B12 (cobolamin) is missing from the vegan diet and very low in the lactovegetarian diet.)
Explanation:
Vitamin B12( cobalamin) is a water soluble vitamin that is essential in the formation of red blood cells. It also serves as a coenzyme in the metabolic reaction of the body. Such reaction includes: 
- the remethylation of methionine from homocysteine which is catalyzed by methionine synthase and requires methylcobalamin.
The deficiency of vitamin B12 can lead to the following:
- elevated homocysteine , 
- an increase in methylmalonate 
This is due to deficiencies in methionine synthase and methylmalonic acid mutase, respectively in individuals on vegan diet for several years.
Vegans are vegetarians that don't include diary or animal products in their meals. This predisposes them to lack of Vitamin B12. Dairy products provide some vitamin B12 in the lactovegetarian diet. Therefore statement 1 is the correct answer, thanks.