Answer:
Option B.
Step-by-step explanation:
The demand function is
[tex]q=7000-100p[/tex]
where p is price.
Solve the demand equation for p.
[tex]100p=7000-q[/tex]
[tex]p=\dfrac{7000-q}{100}[/tex]
The revenue function is
[tex]R(q)=qp[/tex]
Substitute the value of p in the above function.
[tex]R(q)=q(\dfrac{7000-q}{100})[/tex]
[tex]R(q)=\dfrac{7000q-q^2}{100}[/tex]
Differentiate with respect to q.
[tex]R'(q)=\dfrac{7000-2q}{100}[/tex]
Equate R'(q)=0,
[tex]\dfrac{7000-2q}{100}=0[/tex]
[tex]7000=2q[/tex]
Divide both sides by 2.
[tex]3500=q[/tex]
Therefore, the correct option is B.