A source is delivering maximum power to a resistance through a network. The ratio of power delivered to the source power

A source is delivering maximum power to a resistance through a network. The ratio of power delivered to the source power

(a) is always 0.5
(b) may be 0.5 or less
(c) may be 0.5 or less or more
(d) may be 0.5 or more

Ans. (b) may be 0.5 or less