The obd-ii catalytic converter monitor uses sensor(s) to monitor catalytic converter efficiency. a. front and rear catalyst temperature b. a throttle position c. front and rear o2 d. an engine coolant temperature

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.