The sum of any two rational numbers is always rational; therefore, we can write the result as a fraction.
For example,
1/2 + 2/3 = 3/6 + 4/6 = 7/6
In more general terms
a/b + c/d = (ad+bc)/(bd)
We cannot divide by zero so neither b nor d can be zero.
Final Answer: Choice A) It can always be written as a fraction