Ta có:
\(\dfrac{S}{3,5}\le Z\le\dfrac{S}{3}\)
\(\Leftrightarrow\) \(\dfrac{10}{3,5}\le Z\le\dfrac{10}{3}\)
\(\Leftrightarrow\) \(2,9\le Z\le3,3\)
\(\Rightarrow Z=3=P=E\)
\(\Rightarrow N=10-2Z=10-2\cdot3=4\)
Vậy \(A=Z+N=3+4=7\)
Chọn D
Chúc bn học tốt!