Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open

A. at sea level

B. at the top of Mt. Everest

C. at a place in a valley below sea level

D. in an aeroplane flying at a height of 10,000 m with inside pressure maintained at the sea level

Radio telescopes are better than optical telescopes because

A. they can detect faint galaxies which no optical telescope can

B. they can work even in cloudy conditions

C. they can work during the day and night

D. All of the above