Two batteries of e.m.f $4 \text{ V}$ and $8 \text{ V}$ with internal resistance $1 \Omega$ and $2 \Omega$ respectively are connected in a circuit with a resistance of $9 \Omega$ as shown in the figure. The current and potential difference between the points $P$ and $Q$ is

• A
  $\frac{1}{3} \text{ A}$ and $4 \text{ V}$
• B
  $\frac{1}{3} \text{ A}$ and $3 \text{ V}$
• C
  $\frac{1}{2} \text{ A}$ and $5 \text{ V}$
• D
  $\frac{1}{6} \text{ A}$ and $3 \text{ V}$