Answer:
Gram-positive bacteria, fungi, endospores, prions
Explanation:
The above mentioned answer is in increasing order which are resistant to chemical biocides.
Gram positive bacterias are the easiest to destroy, then fungi is difficult than bacteria, endospore is more difficult to remove or destroy by chemical biocides and prions are the most resistant protein particles to the chemical biocides.
Prions are very difficult to kill by standard sterilization and disinfection procedures.