Answer: washing hands before the lab
Step-by-step explanation:
Lab environment requires the maintenance of clean ambiance so that no contaminants are added to the samples under observations. As if the contaminants are administered inside the samples the analytical process will get disturbed and errors may appear in the outcome.
Washing hands before the lab is the correct option this is because of the fact that it will prevent the contamination of the glasswares, instruments and even the samples which are taken for analysis.