The correct answer is B. A user manual
Step-by-step explanation:
A functional text is a type of text written with the purpose of helping readers solve a problem or complete a process that is part of their daily life, this means different to most texts functional texts are specific and necessary to perform a certain task. Due to this functional text include only the necessary information and are mainly short and concise. Examples of these texts include recipes, manuals, signs on the street, menus, among others. According to this, the one that is a functional text is a user manual because this text has the purpose of guiding readers to use a device or solve a problem with it and therefore has a specific function related to a task which is the main feature of functional texts.