Explanation:
the slope of a line or linear equation is always the factor of the driving variable.
usually in the form of
y = ax + b
x is the variable, and a the slope.
but in our case the variable is called "n".
it does not matter, the same principle applies.
the slope is the factor of n : 1050.
and as the slope is always the ratio y/x, we are looking for a fraction form, and that would be 1050/1.
so, the third answer is correct.