B

Step 1: Identify the circuit components.
The circuit consists of a voltage source (30 V) and several voltage drops: +2 V, +1 V, -5 V, and -3 V, along with the unknown voltage drop V₁.

Step 2: Apply Kirchhoff's Voltage Law (KVL).
KVL states that the sum of the potential differences (voltage) around a closed loop in a circuit must equal zero. The equation can be formulated as follows:
\[ 30 - 5 - 3 + 2 + 1 + V_1 = 0 \]

Step 3: Simplify the equation.
Combine the constant voltages:
\[ 30 - 5 - 3 + 2 + 1 = 25 \]

Now substituting back into KVL equation:
\[ 25 + V_1 = 0 \]

Step 4: Solve for V₁.
\[ V_1 = -25 \]

Step 5: Conclusion.
The unknown voltage drop V₁ is -25 V, which corresponds to option B.