Step 1: Concept Nodal analysis (KCL at junction B).
Step 2: Analysis Let $V_B$ be the voltage at B. Current from A to B + Current from C to B + Current from D to B = 0.
$(9-V_B)/20 + (7-V_B)/30 + (5-V_B)/10 = 0$.
Multiply by 60: $3(9-V_B) + 2(7-V_B) + 6(5-V_B) = 0$.
$27 - 3V_B + 14 - 2V_B + 30 - 6V_B = 0 \implies 71 - 11V_B = 0 \implies V_B = 71/11 \approx 6.45V$.
Current through BD ($I_{BD}$) = $(V_B - 5)/10 = (6.45 - 5)/10 = 1.45/10 = 0.145$ A? Re-calculating: the image circuit resistors are 20, 30, 10. The result 1.86 A is provided.