A student solving for the acceleration of an object has applied appropriate physics principles and obtained the expression a=a1 + F/m where a1 = 3.00 meter/ second2 F=12.0 kilogram.meter/second2 and m=7.00 kilogram. First which of the following is the correct step for obtaining a common denominator for the two fractions in the expression in solving for a?

a. (m/m times a1/1) + (1/1 times F/m)
b. (1/m times a1/1) + (1/m times F/m)
c. (m/m times a1/1) + (F/F times F/m)
d. (m/m times a1/1) +(m/m times F/m )

Please choose the correct answer choice I put the word times to repersent the dot of multiplcation .