Some problems with use of DNA analysis for forensic evidence may occur because of

identical twins.

not enough of a sample.

contaminated samples.

degraded samples.

All of the above.

Answer: Option D " all of the above "

Explanation: DNA can be a great source of information when used as a forensic evidence. This technique has many advantages and disadvantages when used as a source of information in case of crime.

Identical twins: There are some common fragments of DNA that is same in identical twins so it can be a difficulty in deciding the criminal.

Not enough of a sample: DNA should be present in a detectable amount to be used an sample for evidence, less than this detectable amount is a waste and cannot be used as a sample for evidence.

Contaminated and degraded sample: If the sample of DNA is contaminated or degraded then the result might be incorrect and might not be used as a sample for forensic evidence.

Hence, the correct answers are all of the above.