Which of these rules should be followed while writing scientific name of an organism?
(a)    Biological names are generally in Latin and written in italics.  
(b)   The specific epithet and genus in a biological name, when handwritten, are separately underlined.
(c)    First letter of specific epithet should be in uppercase    
(d)    First letter of genus should be in uppercase

Biological names are generally in Latin and written in italics. They are Latinised or derived from Latin irrespective of their origin. Both the words in a biological name, when handwritten, are separately underlined, or printed in italics to indicate their Latin origin. The first word denoting the genus starts with a capital letter while the specific epithet starts with a small letter. It can be illustrated with the example of Mangifera indica.