All are understandable but I'd say 'D'. A and B are incorrect in terms of grammar. C should be '전원을 켤 수 없어서 답답해요'. (check your spelling '켤') Breaking it down, can - 할수있다. can't - 할수 없다. turn on the power - 전원을 켜다. Making them a sentence, 'can't turn on the power' - 전원을 켤수 없다. A and B should be '전원이 안 켜지다' or '전원이 켜지지 않다' meaning 'The power doesn't turn on ' not 'can't turn on the power'. In here, the subject should be ' the power' not 'I'. Also '전원이 켜지지 않다' is more common and natural. '안 켜지다' has to be '(the power) will not turn on' or '(the power)wouldn't turn on'. so that, your sentence can be translated as '미안해요 전원이 안 켜져서 답답해요' or '전원을 켤 수가 없어서 답답해요'.

-아/어지다 is used to make an adjective or action verb into a passive one. 좋다 to be good - 좋아지다 to get good/better 밝다 to be bright - 밝아지다 to get bright/brighter 켜다 to turn on - 켜지다 to get turned on 끄다 to turn off - 꺼지다 to get turned off

미안해요. 전원을 켤수가 없어요. (a,b,c,d) are passive forms. Active form is more natural. I don't think the expression (좌절했어요) is natural.

나는 거의 절대 제일 대답을 선택할 거야 하지만 아주 인상적었어요.감사합니다.