The correct option is B Input/output, conditional
In the given flowchart, there is an ellipse, a rectangle and a rhombus.
An ellipse is the Terminal.
A rectangle is the Process.
A rhombus is the Decision.
A parallelogram is the Input/output.
There is no parallelogram in the given flowchart. So, the missing symbol is input/output.
The given flowchart has Decision symbols i.e., conditions. That means it is a conditional flowchart.