Answer
A, and B are absorbing power
C is delivering power
Work Step by Step
Looking at A we see that current is coming out the negative terminal, which means we need a sign change to comply with the passive sign convention.
so... $p=-(-12)*25 = 300W$ (absorbed because positive)
B is already in the passive convention
$p = 15*25 = 375W$ (absorbed because positive)
C needs a sign change because current is entering the negative terminal
$p = -27*25 = -675W $ (delivered because negative)
Do a check to see that the sum of the power equals zero
375+300-675 = 0, which means we did the problem correctly.