A voltmeter of 400 W resistance is in parallel with 100 W resistor. And the combination is connected with $\mathbf { 1 0 0 } \mathbf { W }$ resistor and a battery of $\mathbf { 9 }$ volt in series as shown. Find the reading of voltmeter ${ } _ { \Delta V }$\\
(A) 3 volts\\
(B) 4 volts\\
(C) 5 volts\\
(D) 6 volts