Correct option is D
When measuring current using a multimeter, it must be connected in series with the load so that the entire current flowing in the circuit passes through the meter. Current is the flow of electric charge, and to measure it accurately, the measuring device must be placed directly in the path of that flow. This is why an ammeter (or multimeter in current mode) is always connected in series.
A multimeter in current mode has very low internal resistance, allowing current to pass through it with minimal opposition. If it were connected in parallel, it could create a short circuit, potentially damaging the instrument and the circuit.
