Judging from the explanation portion of your answer, it looks like you have completely misunderstood the question.
Programming language standards require a particular representation of data types from implementations of the language, i.e. the language compilers, interpreters, or virtual machines. It is the designers of these compilers, interpreters, and virtual machines who may be given a choice in deciding the representation, not programmers in the corresponding language.
The "Which approach do you think is better and Why?" part of the question requires you to analyze the process of designing a language from two different points of view - that of programmers who builds the language, and that of programmers who writes programs in that language. What may be good for one group of programmers may not be good for the other group. Moreover, what one group may think is good may actually create an ongoing maintenance problem.
For example, if the specification says that integers must be represented as 32 bits that use two's complement representation for negatives, designers of programming languages who port the language to hardware with sign+value representation may have a lot more work to do. On the other hand, programmers writing in a language that does not specify the representation and assuming that the representation would be the same on all platforms may create completely non-portable programs.