Final answer:
The opposite of 'defective' from the given options is 'dedication'. While 'dedication' may not directly mean 'without flaw', it contrasts 'defective' by implying thoroughness or committed quality. The other options represent negative attributes or are unrelated.
Step-by-step explanation:
The opposite of "defective" is option c. Dedication. 'Defective' means having a defect or flaw, so the opposite would be something that is without flaw or is exemplary in quality. The word 'dedication' doesn't exactly match the opposite of 'defective' in terms of product quality, but when considering the attributes or conditions of something, 'dedication' implies a level of commitment or completeness which can be seen as contrast to defective or unfinished.
In context, a better opposite to 'defective' might be 'flawless' or 'perfect,' but given the options presented, 'dedication' is the best choice despite not being a direct antonym. The other options like 'grumble' and 'faulty' represent negative qualities, and 'decisive' is more about the ability to make decisions quickly and effectively, rather than a quality of being without defect.