If $V = 20 \mathrm {~V}$ And the Battery Is Ideal, What Is the Current Through

Multiple Choice

If $V = 20 \mathrm {~V}$ and the battery is ideal, what is the current through $R _ { 3 }$ in the figure?

A) $1.0 \mathrm {~A}$
B) $4.0 \mathrm {~A}$
C) $0.050 \mathrm {~A}$
D) $0.20 \mathrm {~A}$