Q1: Which is a true statement about the circuit in the given circuit?

A The batteries are series-aiding and the total source voltage equals 21 V.

B The batteries are series-opposing and the total source voltage equals 3 V.

C The batteries are series-aiding and the total source voltage equals 3 V.

D    <div class="bix-td-option" id="tdOptionNo_D_130"><span id="lnkOptionLink_D_130" class="mdi mdi-alpha-d-circle-outline"></span></div>
                                                    <div class="bix-td-option-val d-flex flex-row align-items-center" id="tdOptionDt_D_130">
                                                        <div class="flex-wrap">The batteries are <b><i>series-opposing</i></b> and the total source voltage equals 21 V.</div>
                                                    </div>