Final answer:
Scientists cannot find dinosaur DNA because it has decayed over millions of years and is prone to contamination, despite advances in technology for analyzing ancient molecular fossils.
Step-by-step explanation:
The reason scientists can't find dinosaur DNA is mostly due to option 2) Dinosaur DNA has already decayed. Dinosaurs did have DNA, like all living organisms, but DNA begins to degrade soon after death. Over the millions of years, since dinosaurs went extinct, any DNA would have broken down and is unlikely to be recoverable. Although amber can preserve organic materials exceptionally well, the process still eventually leads to the destruction of DNA within trapped specimens, including insects or small creatures from the dinosaur era. Additionally, contamination during the extraction process and the presence of microorganisms further contribute to the difficulty of recovering ancient DNA. Advances in technology may improve our ability to detect and analyze ancient molecular fossils, but for now, the degradation and contamination challenges make finding dinosaur DNA highly improbable.