Answer: D) an emotion
Step-by-step explanation:
Emotion is described as feeling that is accessed through the mental processes. It helps in expressing the responses in behavior of people .There are different emotions such as happiness, sadness, anger, frustration etc.
According to question, Julia is expressing her anger as an emotion because she got yelled in front of everyone in office by her boss for her work.
Other options are incorrect because thought, mood, metal operation and affect are not the factors displayed by anger of Julia as she is displaying her feelings through trashing the magazines. This, the correct option is option(D).