Sec 44ad - professional income

An eligible assessee may opt for this scheme, that means it is applicable at the discretion of the assessee running an eligible business. Is this assumption right? Now a medical practitioner has gross fee of 10 lakhs and maintains proper records as per sec 44AA but his profit is less than 50% of gross earnings, due to expenditure on rent/ car/ medicines/ salaries to staff etc and so does not opt for benefit of 44AD. His profit , say, is about 30% of gross fee. He is not required to get his accounts audited as his gross earning is less than 25 (now 50) lakhs.and he is not opting for 44AD, files his tax return using ITR 4 and not 4S Will he still be compulsorily required to get his accounts audited or declare 50% of gross fee as his income, even if he is not opting for use of 44AD? If so, then how can one say that sec 44AD is discretionary -- it can result in heavy penalty/ cost/ inconvenience to small tax payer professionals whose profit margin is much lower than 50% Kindly enlighten with your views re. correct interpretation of sec 44AD, Can he file ITR 4 as per accounts maintained by him but with out audit? 

Read more at: /experts/ask_query.asp