I think it’s d
If it’s wrong then I’m sorry
First, determine the number of moles of gold.
Number of moles = 
Given mass of gold =
Molar mass of gold = 196.97 g/mol
Put the values,
Number of moles of gold = 
=
or
Now, molarity = 
Put the values, volume of ocean =
Molarity = 
= 
Thus, average molar concentration = 
Answer:
False
Explanation:
In an exothermic process, the reaction gives off heat, and not takes it in. If it takes it in from the surroundings, then it would be endothermic.