28. While there are many definitions of "functional genomics," select the best of these choices: (A) The assignment of function to genes based primarily on genomewide gene expression data using techniques such as microarrays or SAGE (B) The assignment of function to genes based primarily on comprehensive surveys of protein-protein interactions and protein networks (C) The combined use of genetic, biochemical, and cell biological approaches to study the function of a particular gene, its mRNA product, and its corresponding protein product (D) The assignment of function to genes and proteins using genomewide screens and analyses