If \(d=\dfrac{a+b}{1+\frac{ab}{c^2}}, a=\dfrac{c}2,\) and \(b=\dfrac{3c}4,\) what is the value of \(d\) in terms of \(c?\)

A. \(\dfrac{10c}{11}\)

B. \(\dfrac{5c}2\)

C. \(\dfrac{10c}3\)

D. \(\dfrac{10}{11c}\)

E. \(\dfrac{5}{2c}\)

Answer: A

Source: Official Guide