As per the code of the nomenclature, which one of the following is the correct way of writing a biological name?

According to the rules of binomial nomenclature established by Carl Linnaeus and governed by codes like the International Code of Zoological Nomenclature (ICZN), a biological name must consist of two parts: the genus and the specific epithet [3]. The first word, representing the genus, must always be capitalized [2]. The second word, the specific epithet, must never be capitalized, even if it is derived from a proper noun [3]. Both components should ideally be italicized in print or underlined when handwritten to indicate their Latinized nature [2]. For the organism in question, 'Amoeba' is the genus and 'proteus' is the specific epithet [1]. Therefore, 'Amoeba proteus' is the only correct format as it follows the mandatory capitalization convention where the genus starts with an uppercase letter and the species remains entirely lowercase [3].

Sources

1. [3] https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=5775
2. [2] https://en.wikipedia.org/wiki/Amoeba_proteus
3. [1] https://uou.ac.in/sites/default/files/slm/ZO(N)-202.pdf