Answer:
Externalities are costs (negative externalities) or benefits (positive externalities), which are not reflected in free market prices. ... Market failure is a situation in which the free market leads to a misallocation of society's scarce ... and the killing of fish is not a cost that it would directly have to bear
Answer : The correct option is, (B)
Explanation :
Balance equation : Balanced equation are those equation in which the number of atoms of each element and the total charge must be same on products side and reactants side.
In the given options, only option (B) equation has correct formula and also a balanced equation.

while the other options has incorrect formulas and also an unbalanced equations.
The correct equation for option A is, 
The correct equation for option C is, 
The correct equation for option D is, 
Hence, the correct answer is, (B) 
The answer to your question is
D: Unshared Pair
Hope this helps you :))))
We can rephrase the statement with a little more specificity in order to understand the answer here.
The mass of the products can never be more than the The mass that is expected.