Consider the following types of vehicles:I.Full battery electric vehiclesII.Hydrogen fuel cell vehiclesIII.Fuel cell-electric hybrid vehiclesHow many of the above are considered as alternative powertrain vehicles?

1. A

   Only one

   Only one. Battery-electric and hydrogen fuel-cell are both alternative powertrains, so the count is not one.

2. B

   Only two

   Only two. That drops the fuel-cell-electric hybrid, which the official key counts as a third listed type.

3. C

   All the three

   All the three. A full BEV, a hydrogen FCEV, and a fuel-cell-electric hybrid are all treated as alternative powertrain vehicles on this paper.

4. D

   None

   None. These are electric-traction architectures, not a conventional ICE-only driveline.

Summary. Official Set A key is (c) all three. An alternative powertrain here means propulsion other than a plain internal-combustion driveline. A full battery-electric vehicle stores electricity and drives a motor. A hydrogen fuel-cell vehicle makes electricity on board and also drives a motor. A fuel-cell-electric hybrid still uses a fuel cell, with a battery buffer; UPSC counts it as a third listed type, not as a mere footnote to FCEV. So I, II and III are all in. (a) under-counts; (b) is the coaching split that treats the hybrid as a variant; (d) empties the list.