Step 1: Identify the changing feature.
Each figure shows two arrowheads, and we watch the angle between them.
Step 2: Measure figure 1 and 2.
The angle is $90^\circ$ in the first figure and $135^\circ$ in the second.
Step 3: Measure figure 3 and 4.
It becomes $180^\circ$ (a straight line) and then $225^\circ$.
Step 4: Spot the rule.
The angle grows by $45^\circ$ each step: $90,135,180,225$.
Step 5: Predict figure 5.
The next angle is $225+45=270^\circ$, which looks like a right-angle corner viewed from the reflex side.
Step 6: Match the option.
Figure A shows that $270^\circ$ configuration.
\[ \boxed{\text{Fig A}} \]