This answer is not correct. If you change one number in a mathematical expression it will impact the other numbers in the expression. The equilibrium equation is an example of a direct proportion. K is a constant which means that it must not be changed. If you increase either the numerator or denominator of a fraction and if that fraction must equal a constant, then the other number must increase in proportion to the number that was changed.
Let's see what happens by using a simple fraction and changing one of the numbers. The fraction 1/2 = 0.5. If the 1 is changed to a 3, then the 2 must be changed to a 6 (3 times as much) in order for the fraction to still equal 0.5...(3/6 = 0.5). If you think in terms of a simple relationship like this, then it is easy to remember how this change takes place. Now try to answer the question...remember that you are changing the numerator of the fraction by increasing the amount of calcium phosphate.