Answer:
processing
Step-by-step explanation:
The flow chart is a diagram that shows the activity of the program, peoples or things.
Flowchart symbol and meaning in the options:
1. Processing: it is a rectangular shape block which is used for variable declaration or assignment.
2. I/0: it is a parallelogram in shape which is used for input or output.
3. Parallelogram: it is used for input or output.
4. diamond: it is used for decisions or conditions.
Therefore, the correct option is a. Processing is the one that is used for the assignment statement.