Final answer:
To find recent scientific articles on Covid19, PubMed is the most suitable database as it provides extensive biomedical literature, including references and abstracts on life sciences.
Step-by-step explanation:
If you want to find recent scientific articles on Covid19, the best database to search would be C) PubMed. PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. It is maintained by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM), which is part of the National Institutes of Health (NIH). PubMed includes millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Covid19 being a significant biomedical topic, a plethora of recent and archived scientific articles related to it can be found on PubMed.
NCBI GenBank is also a valuable resource maintained by NCBI, useful for genetic sequence data, but for comprehensive literature, PubMed is more suitable. Other databases like PDB (Protein Data Bank) and Uniprot are more specialized towards protein structures and sequences, respectively. While those databases are invaluable in their own contexts, they are not the primary sources for comprehensive scientific literature on Covid19.