Which of the following is a fundamental unit?

Think it through first, then pick an option.

a Hz
b Cd
c J
d Pa

Answer and explanation

Correct answer: b Cd

The candela is the unit of luminous intensity, one of the seven fundamental units. The board prints the symbol as Cd, but the symbol of the candela is cd.

Why the other options are wrong

a Hz: Hz (hertz) is the unit of frequency; it is not in the list of the seven fundamental units.
c J: J (joule) is the unit of energy; it is not in the list of the seven fundamental units, so it is not a fundamental unit.
d Pa: Pa (pascal) is the unit of pressure; it is not in the list of the seven fundamental units, so it is not a fundamental unit.