Inference is basically something which is not directly stated in pargraph . You should derive it with help of premises.
so any option which directly states something which is already present in paragraph would be incorrect.
(A) If the nursing profession solves the problems of low wages and high-stress working conditions, it will attract able applicants in greater numbers than it currently does. - Restates what its there in premises - so incorrect
(B) The nursing profession will have to lower its entrance standards if the pool of able applicants to nursing school does not increase beyond the current level. - Again restates info for premises - so incorrect
(C) If the nursing profession solves the problems of low wages and high-stress working conditions, high quality health care will be maintained - Fine keep this on hold
(D) If the nursing profession fails to solve the problems of low wages and high stress working conditions, there will soon be an acute shortage of nurses - incorrect , they can lower standards and increase greater number of admits
(E) The current high quality of health care will not be maintained if the problems of low wages and high-stress working conditions in the nursing profession are no solved. - Fine keep this on hold
Now between C and E ,
C states , if X happnes Y will happen
E States , Y will happen is X does not happen
Read last statement in premises , It clearly supports Option E and hence E is correct answer