1 kilowatt hour is the amount of electric energy consumed when 1 kilowatt power is used for 1 hour in an electric circuit. Express it in joules.

A

$$ 6.3 \times 10^{6} J $$

B

$$ 6.3 \times 10^{5} J $$

C

$$ 3.6 \times 10^{6} J $$

D

$$ 4.6 \times 10^{6} J $$