Answer
(a) In series
(b) III
Work Step by Step
(a) We know that the fuse should always be connected in series because when the fuse is blown out, it makes an open circuit and the appliances are protected from high current.
(b) We know that the best explanation is option (III) -- that is, with the fuse connected in series, the current in the circuit drops to zero as soon as the fuse burns through.
