Middleware for cloud database applications is commonly written as sections of code written in a programming or scripting language that are executed by another program

Middleware for cloud database applications is commonly written as scripts—short sections of code written in a programming or scripting language that are executed by another program. A script language is used for server side scripting language that can change a specific data on the server. Examples of these are PHP, JSP, Perl, Python, etc.

Iwould go with either b or c, not sure which one.