D. q(x)
it is the only exponential function
y is multiplied by 2 each time c increases by 1
For this case we have that by definition, the standard way to write the equation of a line, is given by:

Where a, b and c are integers.
Given 
We can write it in the standard way:

and by the previous definition, the numbers a, b and c must be integers.
Thus, we multiply the equation by 2, on both sides so as not to alter the equality.


Thus, the equation of
, in its standard form is given by:

Answer:
Option B