question

What is an attainable standard?
A standard which is based on currently attainable working conditions
A standard which is established for use over a long period, which is used too show trends
A standard which can be attained under perfect operating conditions and which includes no allowance for wastage spoilage machine breakdowns and other inefficiencies
A standard which can be attained if production is carried out efficiently, machines are operated properly and/or materials are used properly. Some allowance is made for waste and inefficiencies.
Why the first statement is not the correct answer. Also which type of standard is the second statement